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04 05 06 07 08 09 10 11 12 13 14 15
16 17 18 19 20 21 22 RFC 4171
Internet Draft Kevin Gibbons
<draft-ietf-ips-isns-04.txt> Josh Tseng
Expires December 2001 Charles Monia
Nishan Systems
Franco Travostino
Nortel Networks
Ken Hirata
Vixel Corporation
Mark Bakke
Cisco Systems
John Dowdy
IBM
Howard Hall
Pirus Networks
June 2001
iSNS Internet Storage Name Service
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026 [1].
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts. Internet-Drafts are draft documents valid for a maximum of
six months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet- Drafts
as reference material or to cite them other than as "work in
progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Acknowledgements
Numerous individuals contributed to the creation of this draft
through their careful review and submissions of comments and
recommendations. We acknowledge the following persons for their
technical contributions to this document: John Hufferd (IBM),
Julian Satran (IBM), Kaladhar Voruganti(IBM), Joe Czap (IBM), Jim
Gibbons, Tseng, Monia Standards Track
iSNS June 2001
Hafner (IBM), Yaron Klein (Sanrad), Larry Lamers (SAN Valley), Jack
Harwood (EMC), David Black (EMC), David Robinson (Sun), and Marjorie
Krueger (HP).
Comments
Comments should be sent to the IPS mailing list (ips@ece.cmu.edu) or
to the authors.
Table of Contents
Status of this Memo...................................................1
Acknowledgements......................................................1
Comments..............................................................2
1. Abstract.....................................................6
2. Conventions used in this document............................6
3. iSNS Overview................................................6
3.1 iSNS Architectural Components................................7
3.1.1 iSNS Protocol (iSNSP)........................................7
3.1.2 iSNS Client..................................................7
3.1.3 iSNS Server..................................................7
3.1.4 iSNS Database................................................7
3.1.5 iSCSI........................................................7
3.1.6 iFCP.........................................................7
3.2 iSNS Functional Components...................................7
3.2.1 Name Registration Service....................................8
3.2.2 Discovery Domain and Login Control Service...................8
3.2.3 State Change Notification Service............................9
3.3 iSNS and Domain Name System (DNS)...........................10
3.4 iSNS and LDAP...............................................10
3.5 iSNS Server Discovery.......................................11
3.6 iSNS and NAT................................................11
3.7 Interactions Between iSNS Infrastructures...................12
3.8 Deployment Architecture Diagram.............................14
4. iSNS Object Model...........................................14
4.1 NETWORK ENTITY Object.......................................15
4.2 PORTAL Object...............................................15
4.3 STORAGE NODE Object.........................................15
4.4 FC DEVICE Object (iFCP Only)................................15
4.5 DISCOVERY DOMAIN Object.....................................15
4.6 DISCOVERY DOMAIN SET Object.................................15
4.7 iSNS Database Model.........................................15
5. iSNS Implementation Requirements............................16
5.1 iSCSI Requirements..........................................16
5.1.1 Required Attributes for Support of iSCSI....................16
5.1.2 Attribute Descriptions for iSCSI Storage Systems............17
5.1.3 Example iSCSI Object Model Diagrams.........................18
5.1.4 Required Commands and Response Messages for Support of iSCSI20
Gibbons, Tseng, Monia Standards Track 2
iSNS June 2001
5.2 iFCP Requirements...........................................21
5.2.1 Required Attributes for Support of iFCP.....................21
5.2.2 Attribute Descriptions for iFCP Gateways and FC devices.....22
5.2.3 iFCP Attribute Requirements.................................24
5.2.3.1 Port_ID.....................................................24
5.2.4 Example iFCP Object Model Diagram...........................24
5.2.5 Required Commands and Response Messages for Support of iFCP.25
5.3 Attribute Descriptions for Discovery Domain Registration....26
5.4 Use of TCP For iSNS Communication...........................27
5.5 Use of UDP For iSNS Communication...........................28
6. iSNS Message Attributes.....................................28
6.1 iSNS Attribute Summary......................................28
6.2 Entity Identifier-Keyed Attributes..........................30
6.2.1 Entity Identifier (EID).....................................30
6.2.2 Entity Protocol.............................................31
6.2.3 Management IP Address.......................................31
6.2.4 Entity Registration Timestamp...............................31
6.2.5 Protocol Version Range......................................31
6.2.6 Registration Period.........................................32
6.2.7 Entity Certificate..........................................32
6.3 Portal-Keyed Attributes.....................................32
6.3.1 Portal IP-Address...........................................32
6.3.2 Portal TCP/UDP Port.........................................32
6.3.3 Portal Symbolic Name........................................33
6.3.4 Entity Status Inquiry Interval..............................33
6.3.5 ESI/SCN UDP Port............................................33
6.3.6 Portal Group................................................34
6.3.7 Portal Certificate..........................................34
6.4 iSCSI Node-Keyed Attributes.................................34
6.4.1 iSCSI Name..................................................34
6.4.2 iSCSI Node Type.............................................34
6.4.3 iSCSI Node Alias............................................35
6.4.4 iSCSI Node SCN Bitmap.......................................35
6.4.5 iSCSI Node Certificate......................................35
6.5 iFCP Node-Keyed Attributes..................................35
6.5.1 iFCP Node Port Name (WWPN)..................................36
6.5.2 Port ID.....................................................36
6.5.3 Port Type...................................................36
6.5.4 iFCP Node Port Symbolic Name................................36
6.5.5 iFCP Node Fabric Port Name (FWWN)...........................37
6.5.6 FC Hard Address.............................................37
6.5.7 FC Port IP Address..........................................37
6.5.8 FC Class of Service (COS)...................................37
6.5.9 FC FC-4 Types...............................................37
6.5.10 FC FC-4 Descriptor..........................................37
6.5.11 FC FC-4 Features............................................38
6.5.12 iFCP Node SCN Bitmap........................................38
Gibbons, Tseng, Monia Standards Track 3
iSNS June 2001
6.5.13 iFCP Node Certificate.......................................38
6.5.14 iFCP Node Type.............................................38
6.6 iFCP FC Device Node-Keyed Attributes........................38
6.6.1 iFCP FC Device Node Name (WWNN).............................39
6.6.2 iFCP FC Device Symbolic Name................................39
6.6.3 FC Device IP Address........................................39
6.6.4 FC Device IPA...............................................39
6.6.5 FC Device Certificate.......................................39
6.7 Other Attributes............................................39
6.7.1 FC-4 Type Code..............................................39
6.7.2 Preferred ID................................................40
6.7.3 Assigned ID.................................................40
6.7.4 Space_Identifier............................................40
6.8 Discovery Domain Registration Attributes....................40
6.8.1 iSNS Discovery Domain Attribute Summary.....................40
6.8.2 DD Set ID Keyed Attributes..................................41
6.8.2.1 Discovery Domain Set ID (DDS ID)............................41
6.8.2.2 Discovery Domain Set Symbolic Name..........................41
6.8.2.3 Discovery Domain Set Status.................................41
6.8.2.4 Discovery Domain Set Member.................................42
6.8.3 DD ID Keyed Attributes......................................42
6.8.3.1 Discovery Domain ID (DD ID).................................42
6.8.3.2 Discovery Domain Symbolic Name..............................42
6.8.3.3 Discovery Domain iSCSI Node Member..........................42
6.8.2.4 Discovery Domain iFCP Node Member...........................42
6.9 Vendor-Specific Attributes..................................42
6.10 Company OUI.................................................43
7. iSNSP Message Format........................................43
7.1 iSNSP PDU Header............................................43
7.1.1 iSNSP Version...............................................43
7.1.2 iSNSP Function ID...........................................43
7.1.3 iSNSP PDU Length............................................44
7.1.4 iSNSP Flags.................................................44
7.1.5 iSNSP Transaction ID........................................44
7.1.6 iSNSP Sequence ID...........................................44
7.2 iSNSP Message Segmentation and Reassembly...................44
7.3 iSNSP Message Payload.......................................45
7.3.1 Attribute Value 4-Byte Alignment............................45
7.4 iSNSP Response Error Codes..................................45
7.5 Message Authentication......................................46
7.6 Registration and Query Messages.............................47
7.6.1 Source Attribute............................................48
7.6.2 Key Attributes..............................................49
7.6.3 Delimiter Attribute.........................................49
7.6.4 Operating Attributes........................................49
7.6.4.1 Operating Attributes for Query and Get Next Requests........49
7.6.5 Registration and Query Message Types........................50
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7.6.5.1 Register Device Attribute Request (RegDevAttr)..............50
7.6.5.1.1 Update Flag................................................51
7.6.5.2 Device Attribute Query Request (DevAttrQry).................51
7.6.5.3 Device Get Next Request (DevGetNext)........................52
7.6.5.4 Deregister Device Request (DeregDev)........................52
7.6.5.5 SCN Register Request (SCNReg)...............................53
7.6.5.6 SCN Deregister Request (SCNDereg)...........................54
7.6.5.7 SCN Event (SCNEvent)........................................54
7.6.5.8 State Change Notification (SCN).............................55
7.6.5.9 DD Register (DDReg).........................................56
7.6.5.10 DD Deregister (DDDereg).....................................56
7.6.5.11 DDS Register (DDSReg).......................................57
7.6.5.12 DDS Deregister (DDSDereg)...................................57
7.6.5.13 Entity Status Inquiry (ESI).................................58
7.6.5.14 Name Service Heartbeat (Heartbeat)..........................58
7.6.5.15 Request Switch ID (RqstSwId)................................59
7.6.5.16 Release Switch ID (RlseSwId)................................60
7.6.5.17 Get Switch IDs (GetSwIds)...................................60
7.7 Response Messages...........................................60
7.7.1 Error Code..................................................61
7.7.2 Key Attributes in Response..................................61
7.7.3 Delimiter Attribute in Response.............................61
7.7.4 Operating Attributes in Response............................61
7.7.5 Registration and Query Message Types........................62
7.7.5.1 Register Device Attribute Response (RegDevRsp)..............62
7.7.5.2 Device Attribute Query Response (DevAttrQryRsp).............62
7.7.5.3 Device Get Next Response (DevGetNextRsp)....................62
7.7.5.4 Deregister Device Response (DeregDevRsp)....................63
7.7.5.5 SCN Register Response (SCNRegRsp)...........................63
7.7.5.6 SCN Deregister Response (SCNDeregRsp).......................63
7.7.5.7 SCN Event Response (SCNEventRsp)............................63
7.7.5.8 SCN Response (SCNRsp).......................................63
7.7.5.9 DD Register Response (DDRegRsp).............................64
7.7.5.10 DD Deregister Response (DDDeregRsp).........................64
7.7.5.11 DDS Register Response (DDSRegRsp)...........................64
7.7.5.12 DDS Deregister Response (DDSDeregRsp).......................64
7.7.5.13 Entity Status Inquiry Response (ESIRsp).....................64
7.7.5.14 Request Switch ID Response (RqstSwIdRsp)....................65
7.7.5.15 Release Switch ID Response (RlseSwIdRsp)....................65
7.7.5.16 Get Switch IDs Response (GetSwIdRsp)........................65
7.8 Vendor Specific Messages....................................65
8. Security Considerations.....................................66
8.1 Data Integrity and Authentication...........................66
8.2 Confidentiality.............................................66
8.3 Security Model..............................................66
9. References..................................................66
10. Author's Addresses..........................................67
Gibbons, Tseng, Monia Standards Track 5
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Full Copyright Statement.............................................68
A.1 iSCSI Initialization Example................................69
A.1.1 Simple iSCSI Target Registration............................70
A.1.2 Target Registration and DD Configuration....................71
A.1.3 Initiator Registration and Target Discovery.................72
1. Abstract
This document provides a generic framework centering around use of
the iSNS for discovery and management of iSCSI and Fibre Channel
(FCP) storage devices in an enterprise-scale IP storage network.
iSNS is an application that stores iSCSI and FC device attributes
and monitors their availability and reachability in an integrated IP
storage network. Due to its role as a consolidated information
repository, iSNS provides for more efficient and scalable management
of storage devices in an IP network.
2. Conventions used in this document
iSNS refers to the framework consisting of the storage network model
and associated services.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC-2119 [2].
All frame formats are in big endian network byte order.
3. iSNS Overview
The objective of iSNS is to facilitate scalable configuration and
management of iSCSI and Fibre Channel (FCP) storage devices in an IP
network. iSNS allows the administrator to go beyond a simple
device-by-device management model, where each storage device is
manually and individually configured with its own list of known
initiators and targets. Using the iSNS, each storage device
subordinates its discovery and management responsibilities to the
iSNS server. The iSNS server thereby serves as the consolidated
management contact through which administrator workstations can
configure and manage the entire storage network.
iSNS can be implemented to support iSCSI and/or iFCP protocols as
needed; an iSNS implementation MAY provide support for one or both
of these protocols as desired by the implementer. Implementation
requirements within each of these protocols is further discussed in
section 5. Use of iSNS is OPTIONAL for iSCSI, and REQUIRED for
iFCP.
When used to support both iSCSI and iFCP protocols, iSNS can be
implemented to facilitate the discovery and management of both iSCSI
and FC devices in an integrated IP/Fibre Channel environment.
Gibbons, Tseng, Monia Standards Track 6
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3.1 iSNS Architectural Components
3.1.1 iSNS Protocol (iSNSP)
The iSNS Protocol (iSNSP) is a flexible and lightweight protocol
that specifies how iSNS clients and servers communicate. It is
suitable for various platforms, including switches and targets as
well as server hosts.
3.1.2 iSNS Client
iSNS clients initiate transactions with the iSNS server using the
iSNSP. iSNS clients are applications that are co-resident in the
storage device, and can register deviceÆs attribute information,
download information about other registered clients in a common DD,
and receive asynchronous notification of topology events that occur
in their DD(s). Management stations are a special type of iSNS
client that have access to all DDs stored in the iSNS.
3.1.3 iSNS Server
The iSNS server responds to iSNS protocol queries and requests, and
initiates iSNS protocol State Change Notifications. Properly
authenticated information submitted by a registration request is
stored in an internal or external iSNS database.
3.1.4 iSNS Database
The iSNS database is the information repository for the iSNS
server(s). It maintains information about iSNS client attributes.
A directory-enabled implementation of iSNS may store client
attributes in an LDAP directory infrastructure.
3.1.5 iSCSI
iSCSI (Internet SCSI) is an encapsulation of SCSI for a new
generation of storage devices interconnected with TCP/IP.
3.1.6 iFCP
iFCP (Internet FCP) is a gateway-to-gateway protocol designed to
interconnect existing Fibre Channel and SCSI devices using TCP/IP.
iFCP maps the existing FCP standard and associated Fibre Channel
services to TCP/IP.
3.2 iSNS Functional Components
There are three main functional components of the iSNS:
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1) A Name Service Providing Storage Resource Discovery
2) Discovery Domain (DD) and Login Control Service
3) State Change Notification Service
3.2.1 Name Registration Service
The iSNS provides a registration function to allow all entities in a
storage network to register and query the directory. Both targets
and initiators can register in the iSNS, as well as query for
information about other initiators and targets. This allows, for
example, a client initiator to obtain information about target
devices from the iSNS server. This service is modeled on the Fibre
Channel Generic Services Name Server described in FC-GS-3, with
extensions, operating within the context of an IP network.
In order to maintain consistency between DNS Name-to-IP address
mappings stored in the iSNS, and the same mappings which may exist
in DNS servers, a common backend database storing such mappings may
be implemented to support both DNS and iSNS. This backend database
can be based upon a standard network directory service such as LDAP.
The naming registration service also provides the ability to obtain
a network unique Domain ID for iFCP gateways when required.
3.2.2 Discovery Domain and Login Control Service
The Discovery Domain (DD) Service facilitates the partitioning of
iSNS client devices into more manageable groupings for
administrative and login control purposes. This allows the
administrator to limit the login process to the more appropriate
subset of targets registered in the iSNS. iSNS clients must be in
at least one common DD in order to obtain information about each
other. iSNS clients can be a member of multiple DD's
simultaneously.
The DD information stored in the iSNS can be used by various
enforcement points in the network to configure security and access
control policy. For example, a DD-aware switch can block storage
initiators from accessing targets that are not in the same DD, even
if the initiator somehow obtained address information for a target
outside of its DD. This functionality is the equivalent of the
ôHard Zoningö functionality in a Fibre Channel network.
Login Control allows targets to subordinate their access control
policy to the iSNS. The target node or device downloads the list of
authorized initiator nodes or devices from the iSNS. Each node or
device is uniquely identified by an iSCSI Name or Port Name (iFCP).
Only initiator nodes or devices that match the required
identification and authenticating information provided by the iSNS
will be allowed access by that target node or device during session
establishment. If spoofing of initiator identities is a concern,
the target may use the public key certificate of the authorized
initiator, obtained from the iSNS server, to authenticate the
initiator.
Gibbons, Tseng, Monia Standards Track 8
iSNS June 2001
DD's can be managed offline by a separate management workstation,
through the iSNSP or through SNMP. If the target opts to use the
Login Control feature of the iSNS, the target subordinates
management of access control policy (i.e., the list of initiators
allowed to login to that target) to the management workstations that
are manipulating information in the iSNS database.
If administratively authorized, a target can upload its own Login
Control list. This is accomplished using the DDReg message and
listing the iSCSI Name of each initiator to be registered in the
Target's DD.
Depending on the implementation, newly registered devices that have
not explicitly been placed into a DD by the management station MAY
be placed into a "default DD" where they are visible to other
devices in that DD. Other implementations MAY decide that they are
registered with no DD, making them inaccessible to source-scoped
iSNSP messages.
The SOURCE field of every iSNS query and registration message is
used to determine the source of the request and scope the operation
to the set of Discovery Domains that the iSNS client is a member of.
If the SOURCE field contains NULL, the iSNS query and registration
message SHALL BE scoped to the entire contents of the iSNS,
regardless of the configuration of Discovery Domains.
Enabled Discovery Domains (DD's) belong to at least one active
Discovery Domain Sets (DDS's). Discovery Domains that do not belong
to an activated DDS are not enabled.
3.2.3 State Change Notification Service
The State Change Notification (SCN) service allows the iSNS to issue
notifications about network events that affect the operational state
of iSNS clients. The iSNS client has the ability to register for
these notifications of events detected by the iSNS. The types of
events for which SCNs can be sent include change in Discovery Domain
(DD) membership and device registration updates.
The State Change Notification service utilizes the Discovery Domain
Service to control the distribution of notification messages.
Notifications about changes within a DD are limited to members of
that DD.
If the iSNS is unable to service an SCN registration it SHALL reject
the SCN registration request, returning a SCN Registration Rejected
error code. The rejection might occur in situations where the
network size, or current level of SCN registrations, has passed an
implementation-specific threshold. A client not allowed to register
for SCNs SHOULD monitor its sessions with other storage devices
directly.
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iSNS June 2001
The specific notification mechanism by which the iSNS learns of the
events is implementation-specific, but can include examples such as
explicit notification messages from an iSNS client to the iSNS
server, or a hardware interrupt to a switch-hosted iSNS as a result
of link failure. The iSNS is equivalent to the Fibre Channel State
Change Notification service, with extensions, operating within the
context of an IP network.
3.3 iSNS and Domain Name System (DNS)
A directory-enabled iSNS implementation may use LDAP to store iSNS
client attributes. If this is the case, then LDAP can be used to
support both the iSNS and DNS server infrastructures, maintaining
consistency in Domain Name-to-IP address mappings used by DNS and
iSNS.
A detailed description of the Domain Name System (DNS) protocol is
found in [RFC 1035], and is beyond the scope of this document. If a
common LDAP information base is used to support both DNS and iSNS
servers, then Domain-Name-to-IP address mappings for storage devices
can be obtained from either DNS servers or the iSNS.
3.4 iSNS and LDAP
LDAP is a generic protocol to access directory services through the
network. It is a passive service designed to deliver scalable
directory services using a get/set model. Applications designed and
tailored to specific user requirements interact with LDAP for their
generic directory service needs. On the other hand, iSNS is an
application that goes beyond the simple get/set model, and provides
specific capabilities needed to monitor and manage an enterprise-
scale storage network. iSNS is one example of an application that
can leverage the services of LDAP. By layering iSNS on top of LDAP,
the capabilities of both iSNS and LDAP can be leveraged to manage
and scale the enterprise IP storage network.
The iSNS application provides capabilities that LDAP alone is not
designed to achieve. This includes the following:
1) Client Attribute Awareness - The iSNS server application
interprets attribute values submitted by clients in registration
messages, and can take appropriate action based upon specific
registered attribute values. The iSNS server is conscious of the
state of each client.
2) State Change Notification - An iSNS server may initiate
notification messages to clients in the event of a change in the
network, such as the non-availability or reachability of a storage
device, or a specific change in the value of a client attribute.
3) Monitoring of Clients - iSNS provides a Entity Status Inquiry
message to verify the availability and reachability of storage
devices.
Gibbons, Tseng, Monia Standards Track 10
iSNS June 2001
4) Lightweight - iSNSP is a simple and lightweight protocol
suitable for implementation on embedded devices such as switches and
targets. There are no unused or "wasted" features that may bog down
the performance of the host device.
3.5 iSNS Server Discovery
The Service Location Protocol (SLP) provides a flexible and scalable
framework for providing hosts with access to information about the
existence, location, and configuration of networked services,
including the iSNS server. SLP MAY be used by iSNS clients to
discover the IP address of the iSNS server. To implement discovery
through SLP, a Service Agent (SA) should be cohosted in the iSNS
server, and a User Agent (UA) should be in each iSNS client. Each
client multicasts a discovery message requesting the IP address of
the iSNS server(s). The SA responds to this request. Optionally,
the location of the iSNS can be stored in the SLP Directory Agent
(DA).
Note that a complete description and specification of SLP can be
found in [RFC2608], and is beyond the scope of this document.
Additional details on use of SLP to discover iSNS can be found in
the document draft-bakke-iscsi-slp-00.txt.
If SLP is not used, then the IP address of the iSNS server can be
stored in a DHCP server to be downloaded using a DHCP option, such
as any of the reserved site-specific option codes (from 128 to 255).
Another approach is to configure each iSNS client to listen to the
iSNS Name Service Heartbeat message (see section 7.6.5.14). A final
approach would be to manually configure the IP address of the iSNS
server in each iSNS client.
3.6 iSNS and NAT
The existence of NAT will have an impact upon information retrieved
from the iSNS. If the iSNS client exists in a different addressing
domain than the iSNS server, then IP address information stored in
the iSNS server may not be correct when interpreted in the domain of
the iSNS client.
There are several possible approaches to allow operation of iSNS
within a NAT network. The first approach is to require use of the
canonical TCP port number by both targets and initiators when
addressing targets across a NAT boundary, and for the iSNS client to
not query for nominal IP addresses. Rather, an iSNS client
initiator SHALL query for the DNS Fully Qualified Domain Name (i.e.,
Entity Identifier) when seeking addressing information. Once
retrieved, the DNS name can be interpreted in each address domain
and mapped to the appropriate IP address by local DNS servers.
A second approach is to deploy a distributed network of iSNS
servers. Local iSNS servers are deployed inside and outside NAT
boundaries, with each local server storing relevant IP addresses for
their respective NAT domains. Updates among the network of
Gibbons, Tseng, Monia Standards Track 11
iSNS June 2001
decentralized, local iSNS servers are handled using LDAP and using
appropriate NAT translation rules implemented within the update
mechanism in each server.
A final approach is to simply disallow use of NAT in between
communication between the iSNS server and any iSNS client.
3.7 Interactions Between iSNS Infrastructures
Each individual iSNS deployment is designed to be operated in
networks under the control of a single administrative authority.
This administrative authority facilitates a seamless, integrated
policy for iSNS usage, including security, naming and registration
of storage assets, and management of Discovery Domains. Through
leverage of an Internet-based database framework such as LDAP, the
iSNS not only scales to large storage networks, but also to support
interactions among multiple independently managed storage
infrastructures, each managed by its own administrative authority.
The information registered in the iSNS can be shared with other iSNS
servers managed by other administrative authorities through out-of-
band, non-iSNS protocols. By importing registration information
from a remote iSNS server, storage connectivity can be established
to devices managed by that server.
The following examples illustrate possible methods to transfer iSNS
records of devices between autonomous, independently-administered
iSNS servers. In the first example, a back-end LDAP information
base is used to support the iSNS server. The following diagram
illustrates use of the LDAP protocol to import iSNS registration
information from one iSNS server to another. Once the record
transfer of the remote device is completed, it becomes visible and
accessible to local devices on the local iSNS server. This allows
local devices to establish sessions with remote devices (provided
firewall boundaries can be negotiated).
Gibbons, Tseng, Monia Standards Track 12
iSNS June 2001
+-------------------------+ +-------------------------+
|+------+ iSNSP | | iSNSP +-----+ |
||dev A |<----->+------+ | | +------+<----->|dev C| |
|+------+ | | | | | | +-----+ |
|+------+ iSNSP |local | | | |remote| iSNSP +-----+ |
||dev B |<----->| iSNS | | | | iSNS |<----->|dev D| |
|+------+ | | | | | | +-----+ |
|........ +--+---+ | WAN | +---+--+ |
|.dev C'. | | Link | | |
|........ | ============= | |
| | | | | |
| +--+---+ | | +---+--+ |
| | local|<--- <--- <--- <-|remote| |
| | LDAP | | LDAP: | | LDAP | |
| +------+ Xfer "dev C"| +------+ |
+-------------------------+ +-------------------------+
Enterprise Enterprise
Network A Network B
In the above diagram, two business partners wish to share storage
"dev C". Using LDAP, the record for "dev C" can be transfered from
Network B to Network A. Once accessible to the local iSNS in
Network A, local devices A and B can now discover and connect to
"dev C".
+-------------------------+ +-------------------------+
|+------+ iSNSP | | iSNSP +-----+ |
||dev A |<----->+------+ | | +------+<----->|dev C| |
|+------+ | | | | | | +-----+ |
|+------+ iSNSP |local | | | |remote| iSNSP +-----+ |
||dev B |<----->| iSNS | | | | iSNS |<----->|dev D| |
|+------+ | | | | | | +-----+ |
|........ +------+ | WAN | +---+--+ |
|.dev C'. ^ | Link | | |
|........ | ============= v |
| | | | |SNMP |
| | | | | |
| +--+----+ | | v |
| | SNMP |<--- <--- <--- <---- |
| | Mgmt | | SNMP: Xfer "dev C" |
| |Station| | | |
| +-------+ | | |
+-------------------------+ +-------------------------+
Enterprise Enterprise
Network A Network B
The above diagram illustrates a second example of how iSNS records
can be shared. In this case, the iSNS servers are not using LDAP to
store records. This method uses an SNMP-based management station to
manually download the desired record for "dev C", and then directly
upload it to the local iSNS. Once the record is transfered to the
local iSNS in Network A, "dev C" becomes visible and accessible
Gibbons, Tseng, Monia Standards Track 13
iSNS June 2001
(provided firewall boundaries can be negotiated) to other devices in
Network A.
Other methods, including proprietary protocols, can be used to
transfer device records between independently-administered iSNS
servers. Further discussion and explanation of these methodologies
is beyond the scope of this document.
3.8 Deployment Architecture Diagram
The following diagram displays examples of where and how iSNS can be
deployed, and of the various IP-based storage entities that it can
support.
+------------+ +-----------+ +-----------+
| | LDAP | Directory | LDAP | iSNS |
| DNS Server |<-------->| Database |<-------->| Server |
| | | | | |
+------+-----+ +-----+-----+ +-----+-----+
| | |
| DNS | LDAP iSNSP |
|Queries | |
+------+----------------------+----------------------+---------+
| |
| IP Network |
| |
+----+-----------+----------+---------------+------------------+
| | | |
| | +-----+-----+ +------+-----+
| | |iSCSI-/ | |iFCP / |
| | | FC /iSNS | |Switch/iSNS |
| | |Gtwy/Server| | /Server|
| | +----+------+ +-+-------+--+
| | | | |
+----+----+ +----+---+ +---+----+ +----+-+ +---+----+
| iSCSI | | iSCSI | | Fibre | | FC | | Fibre |
|Initiator| | Target | |Channel | |Device| |Channel |
+---------+ +--------+ |Network | +------+ |Network |
+--------+ +--------+
4. iSNS Object Model
iSNS provides the framework for the registration and discovery of
iSCSI devices and Fibre Channel-based devices (using iFCP). This
architecture defines common objects that can be used to represent
components referenced by each of these protocols.
This architecture framework provides elements needed to describe
various storage device objects and attributes that may exist on an
IP storage network. Objects defined in this architecture framework
include SAN, NETWORK ENTITY, PORTAL, STORAGE NODE, STORAGE DEVICE
DISCOVERY DOMAIN, and DISCOVERY DOMAIN SET. Each of these objects
are described in greater detail in the following sections.
Gibbons, Tseng, Monia Standards Track 14
iSNS June 2001
4.1 NETWORK ENTITY Object
The NETWORK ENTITY object is a container of STORAGE NODE objects and
PORTAL objects. It represents a device or gateway that is
accessible from the IP network. All STORAGE NODEs and PORTALs
contained in a NETWORK ENTITY object operate in a coordinated
manner.
4.2 PORTAL Object
The PORTAL object is an IP interface through which access to any
STORAGE NODE within the NETWORK ENTITY can be obtained. A NETWORK
ENTITY must have one or more PORTALs, each of which is usable by
STORAGE NODEs contained in that NETWORK ENTITY to gain access to, or
be accessible from, the IP network.
4.3 STORAGE NODE Object
The STORAGE NODE object is the logical endpoint of an iSCSI or iFCP
connection session. In iFCP, the session endpoint is represented by
the World Wide Port Name (WWPN). In iSCSI, the session endpoint is
represented by the iSCSI Name of the device.
4.4 FC DEVICE Object (iFCP Only)
The FC DEVICE represents the Fibre Channel end node. Although
mostly unused in support of the iFCP storage connection, this object
contains information that may be useful in the management of the
Fibre Channel device.
4.5 DISCOVERY DOMAIN Object
DISCOVERY DOMAINS (DD) are a security and management mechanism used
to partition storage resources. Discovery Domains limit the
discovery process to the administrator-configured subset of relevant
storage devices, preventing initiators from inappropriately
attempting login to devices that they shouldnÆt have access to.
When queried, the iSNS server will provide information only for
storage entities that share at least one common DD. Initiators will
not be able to "see" devices with which they do not have at least
one common DD.
4.6 DISCOVERY DOMAIN SET Object
The DISCOVERY DOMAIN SET (DDS) is a container object for DDÆs.
DDSÆs may contain one or more DDÆs. Similarly, each DD can be a
member of one or more DDSÆs. DDSÆs are a mechanism to store
coordinated sets of DD mappings in the iSNS.
4.7 iSNS Database Model
The following shows the the various objects described above and
their relationship to each other.
Gibbons, Tseng, Monia Standards Track 15
iSNS June 2001
+--------------+ +-----------+
| NETWORK |1 *| |
| ENTITY |----| PORTAL |
| | | |
+--------------+ +-----------+
| 1
|
|
| *
+-----------+ +--------------+ +-----------+ +-----------+
| FC |1 *| STORAGE |* *| DISCOVERY |* *| DISCOVERY |
| DEVICE |----| NODE |----| DOMAIN |----| DOMAIN |
|(iFCP Only)| | | | | | SET |
+-----------+ +--------------+ +-----------+ +-----------+
* represents 0 to many possible relationships
5. iSNS Implementation Requirements
iSNS can be implemented with features to support iSCSI and/or iFCP.
Implementation of support for either or both of these protocols is
OPTIONAL. IF iSNS is implemented to support a particular protocol,
then a minimum set of attributes and iSNSP commands is REQUIRED for
support of that protocol. This section details specific requirements
for support of each of these IP storage protocols.
5.1 iSCSI Requirements
Use of iSNS in support of iSCSI is OPTIONAL. iSCSI devices MAY be
manually configured with the iSCSI Name and IP address of peer
devices, without the aid or intervention of iSNS. iSCSI devices
also MAY use SLP [RFC 2608] to discover peer iSCSI devices.
However, for scaling a storage network to a larger number of iSCSI
devices, use of iSNS is RECOMMENDED.
5.1.1 Required Attributes for Support of iSCSI
The following attributes are available to support iSCSI. Attributes
indicated in the REQUIRED TO IMPLEMENT column MUST be supported by
an iSNS server used to support iSCSI. Attributes indicated in the
REQUIRED TO USE column MUST be supported by an iSCSI device that
elects to use the iSNS.
Gibbons, Tseng, Monia Standards Track 16
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REQUIRED REQUIRED
Object Attribute to Implement to Use
------ --------- ------------ --------
NETWORK ENTITY Entity Identifier * *
Entity Protocol * *
Management IP Address
Timestamp *
Protocol Version Range *
Entity Certificate *
PORTAL IP Address * *
TCP/UDP Port * *
Portal Symbolic Name *
ESI Interval *
ESI Port *
Portal Group *
Portal Certificate *
STORAGE NODE iSCSI Name * *
Node Type * *
Alias/Symbolic Node Name *
SCN Event Bitmap *
Node Certificate *
DISCOVERY DOMAIN DD_ID * *
DD_Symbolic Name *
DISCOVERY DOMAIN DDS Identifier *
SET DDS Symbolic Name *
Status *
All iSCSI user-specified and vendor-specified attributes are
optional to implement and use.
5.1.2 Attribute Descriptions for iSCSI Storage Systems
The iSNS attributes used to represent iSCSI Storage Systems are
shown and described in the following diagram:
Gibbons, Tseng, Monia Standards Track 17
iSNS June 2001
- iSCSI NETWORK ENTITY
|
- Entity Identifier
| By convention this is the DNS name of the
| Portal IP-Address(es). If it is not registered
| the iSNS will assign a unique alphanumeric
| identifier to it.
- Entity Protocol
| Indicates this is an iSCSI registration
- Mgt IP-Address
| If it is not registered then in-band management
| is assumed.
- Timestamp
| Timestamp of last registration update
- Protocol Version Range
| Indicates the iSCSI versions supported
- Entity Certificate
| X.509 certificate bound to the Entity (FQDN)
- PORTAL (1 - n per ENTITY)
| |
| - IP-Address
| - TCP/UDP Port
| | The IP-Addr and Port together uniquely
| | define a portal.
| - Portal Symbolic Name
| - Entity Status Inquiry Interval
| | If 0, no ESI is used to this Portal
| - Entity Status Inquiry Port
| | The port used to receive ESIs
| - Portal Group
| | The aggregation group this portal is a member of
| - Portal Certificate
|
- STORAGE NODE (1 - m per ENTITY)
|
- iSCSI Name
- Node Type (initiator / target / ...)
- Alias/Symbolic Node Name
- SCN Event Bitmap
| Indicates current SCN state
- Node Certificate
5.1.3 Example iSCSI Object Model Diagrams
The following diagram models how a simple iSCSI-based initiator and
target is represented using database objects stored in the iSNS. In
this implementation, each target and initiator is attached to a
single PORTAL. Since the devices shown are iSCSI, the FC DEVICE
object does not apply. All required attributes are also shown in
this diagram:
Gibbons, Tseng, Monia Standards Track 18
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+----------------------------------------------------------------+
| IP Network |
+------------+--------------------------------------+------------+
| |
| |
+-----+------+------+-----+ +-----+------+------+-----+
| | PORTAL | | | | PORTAL | |
| | -IP Addr 1 | | | | -IP Addr 2 | |
| | -TCP Port 1 | | | | -TCP Port 2 | |
| +-----+ +-----+ | | +-----+ +-----+ |
| | | | | | | |
| | | | | | | |
| +--------+ +--------+ | | +-------+ +--------+ |
| | | | | | | |
| | STORAGE NODE | | | | STORAGE NODE | |
| | -iSCSI Name | | | | -iSCSI Name | |
| | -Alias: "server1"| | | | -Alias: "disk1"| |
| | -Type: initiator | | | | -Type: target | |
| | | | | | | |
| +-------------------+ | | +------------------+ |
| | | |
| NETWORK ENTITY | | NETWORK ENTITY |
| -Entity ID (FQDN): | | -Entity ID (FQDN): |
| "strg1.foo.com" | | "strg2.bar.com" |
| -Protocol: iSCSI | | -Protocol: iSCSI |
| | | |
+-------------------------+ +-------------------------+
The object model can be expanded to describe more complex devices,
such as an iSCSI device with more than one storage controller, each
controller accessible through any of multiple PORTAL interfaces.
The storage controllers on this device which can be accessed through
alternate PORTAL interfaces, if any original interface should fail.
The following diagram describes such a device:
Gibbons, Tseng, Monia Standards Track 19
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+---------------------------------------------------------------+
| IP Network |
+-------------------+-----------------------+-------------------+
| |
| |
+------------+------+------+---------+------+------+------------+
| | PORTAL | | PORTAL | |
| | -IP Addr 1 | | -IP Addr 2 | |
| | -TCP Port 1 | | -TCP Port 2 | |
| +-----+ +-----+ +-----+ +-----+ |
| | | | | |
| +---------------+ +---------------------+ +---------------+ |
| +-------+ +----------------+ +-------------------+ +------+ |
| | | | | | | |
| +-------+ +-------+ +------+ +--------+ +--------+ +------+ |
| | | | | | | |
| | STORAGE NODE | | STORAGE NODE | | STORAGE NODE | |
| | -iSCSI Name 1 | | -iSCSI Name 2 | | -iSCSI Name 3 | |
| | -Alias: "disk1"| | -Alias: "disk2"| | -Alias: "disk3"| |
| | -Type: target | | -Type: target | | -Type: target | |
| | | | | | | |
| +-----------------+ +-----------------+ +-----------------+ |
| |
| NETWORK ENTITY |
| -Entity ID (FQDN): "dev1.foo.com" |
| -Protocol: iSCSI |
| |
+---------------------------------------------------------------+
5.1.4 Required Commands and Response Messages for Support of iSCSI
The following are iSNSP messages and responses are available in
support of iSCSI. Messages indicated in the REQUIRED TO IMPLEMENT
column MUST be implemented in iSNS servers used for iSCSI devices.
Messages indicated in the REQUIRED TO USE column must be implemented
in iSCSI devices that elect to use the iSNS.
Gibbons, Tseng, Monia Standards Track 20
iSNS June 2001
REQUIRED TO:
Message Description Abbreviation Func ID Implement Use
------------------- ------------ ------- --------- ---
Register Dev Attr Req RegDevAttr 0x0001 * *
Dev Attr Query Request DevAttrQry 0x0002 * *
Dev Get Next Request DevGetNext 0x0003 *
Deregister Dev Request DeregDev 0x0004 * *
SCN Register Request SCNReg 0x0005 *
SCN Deregister Request SCNDereg 0x0006 *
SCN Event SCNEvent 0x0007 *
State Change Notification SCN 0x0008 *
DD Register DDReg 0x0009 * *
DD Deregister DDDereg 0x000A * *
DDS Register DDSReg 0x000B * *
DDS Deregister DDSDereg 0x000C * *
Entity Status Inquiry ESI 0x000D *
Name Service Heartbeat Heartbeat 0x000E
NOT USED 0x000F-0x0013
RESERVED 0x0014-0x00FF
Vendor Specific 0x0100-0x01FF
RESERVED 0x0200-0x8000
The following are iSNSP response messages used in support of iSCSI:
REQUIRED TO:
Response Message Desc Abbreviation Func_ID Implement Use
--------------------- ------------ ------- --------- ---
Register Dev Attr Rsp RegDevRsp 0x8001 * *
Dev Attr Query Rsp DevAttrQryRsp 0x8002 * *
Dev Get Next Rsp DevGetNextRsp 0x8003 *
Deregister Dev Rsp DeregDevRsp 0x8004 * *
SCN Register Rsp SCNRegRsp 0x8005 *
SCN Deregister Rsp SCNDeregRsp 0x8006 *
SCN Event Rsp SCNEventRsp 0x8007 *
SCN Response SCNRsp 0x8008 *
DD Register Rsp DDRegRsp 0x8009 * *
DD Deregister Rsp DDDeregRsp 0x800A * *
DDS Register Rsp DDSRegRsp 0x800B * *
DDS Deregister Rsp DDSDeregRsp 0x800C * *
Entity Stat Inquiry Rsp ESIRsp 0x800D *
NOT USED 0x800E-0x8013
RESERVED 0x8014-0x80FF
Vendor Specific 0x8100-0x81FF
RESERVED 0x8200-0xFFFF
5.2 iFCP Requirements
In iFCP, use of iSNS is REQUIRED. No alternatives exist for support
of iFCP Naming & Discovery functions. iSNS is integral to the
operation of iFCP, in order to allow iFCP gateways to execute Fibre
Channel S_ID and D_ID address mappings to remote gateways.
5.2.1 Required Attributes for Support of iFCP
Gibbons, Tseng, Monia Standards Track 21
iSNS June 2001
The following table displays attributes that are used by iSNS to
support iFCP. Attributes indicated in the REQUIRED TO IMPLEMENT
column MUST be supported by the iSNS server that supports iFCP.
Attributes indicated in the REQUIRED TO USE column MUST be supported
by iFCP gateways.
REQUIRED REQUIRED
Object Attribute to Implement to Use
------ --------- ------------ --------
NETWORK ENTITY Entity Identifier * *
Entity Protocol * *
Management IP Address
Timestamp *
Protocol Version Range *
Entity Certificate *
PORTAL IP Address * *
TCP/UDP Port * *
Portal Symbolic Name *
ESI Interval *
ESI Port *
Portal Group *
Portal Certificate *
STORAGE NODE Port Name (WWPN) * *
Port_ID * *
Port Type * *
Port Symbolic Name *
FC Fabric Port Name (FWWN) *
FC Hard Address *
FC Port IP Address *
FC Class of Service *
FC FC-4 Types *
FC FC-4 Descriptors *
FC FC-4 Features *
SCN Event Bitmap *
Node Certificate *
FC DEVICE Port Name (WWPN) * *
Node Type * *
Alias/Node Symbolic Name *
FC Node IP Address *
FC Node IPA *
DISCOVERY DOMAIN DD_ID * *
DD_Symbolic Name *
DISCOVERY DOMAIN DDS Identifier *
SET DDS Symbolic Name *
Status *
5.2.2 Attribute Descriptions for iFCP Gateways and FC devices
Gibbons, Tseng, Monia Standards Track 22
iSNS June 2001
The iSNS attributes used to support iFCP gateways are shown and
described in the following figure:
- iSNS Server-Specific
- Preferred_ID
- Assigned_ID
- Space_Identifier
- iFCP NETWORK ENTITY
|
- Entity Identifier
| By convention this is the DNS name of the
| Portal IP-Address(es). If it is not registered
| the iSNS will assign a unique alphanumeric
| identifier to it.
- Entity Protocol
| Indicates this is an iFCP registration
- Management IP-Address
| If it is not registered then in-band management
| is assumed.
- Timestamp
| Last registration update. Maintained by the iSNS.
- Protocol Version Range
| Indicates the iFCP versions supported
- Entity Certificate
| X.509 certificate bound to the Entity (FQDN)
|
- PORTAL (1 - n per ENTITY)
| |
| - IP-Address
| - TCP/UDP Port
| | The IP-Address and Port combined uniquely
| | define a portal.
| - Portal Symbolic Name
| - Entity Status Inquiry Interval
| | 0 if no status inquiry is used
| - Entity Status Inquiry Port
| | The port used to receive ESIs
| - Portal Group
| | The aggregation group this portal is a member of
| - Portal Certificate
|
- STORAGE NODE (1 - k per ENTITY)
|
- Port Name (WWPN)
- Port ID
- Port Type
- Port Symbolic Name
- FC Fabric Port Name (FWWN)
- FC Hard Address
- FC Port IP Address
- FC Class of Service
- FC FC-4 Types
- FC FC-4 Descriptors
Gibbons, Tseng, Monia Standards Track 23
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- FC FC-4 Features
- SCN Bitmap
- Node Certificate
- FC DEVICE (1 - m per ENTITY)
|
- Node Name (WWNN)
- Node Symbolic Name
- FC Node IP-Address
- FC Node IPA
- FC Device Certificate
5.2.3 iFCP Attribute Requirements
5.2.3.1 Port_ID
Port_ID assignments for each STORAGE NODE object within a single
NETWORK ENTITY SHALL be unique. For each NETWORK ENTITY (i.e., iFCP
gateway), no more than one STORAGE NODE can be assigned a given
PORT_ID value.
5.2.4 Example iFCP Object Model Diagram
The iFCP protocol allows native Fibre Channel devices, or Fibre
Channel fabrics connected to an iFCP gateway, to be directly
internetworked using IP.
When supporting iFCP, the iSNS stores Fibre Channel device
attributes, iFCP gateway attributes, and Fibre Channel fabric switch
attributes that might also be stored in an FC name server.
The following diagram shows a representation of a gateway supporting
multiple Fibre Channel devices behind it. The two PORTAL objects
represent IP interfaces on the iFCP gateway that can be used to
access any of the three STORAGE NODE objects behind it. Note that
the FC DEVICE object is not contained in the NETWORK ENTITY object.
However, each FC DEVICE has a relationship to one or more STORAGE
NODE objects.
Gibbons, Tseng, Monia Standards Track 24
iSNS June 2001
+--------------------------------------------------------+
| IP Network |
+--------+-----------------+-----------------------------+
| |
+-+------+------+---+------+------+----------------------+
| | PORTAL | | PORTAL | NETWORK ENTITY |
| | -IP Addr 1 | | -IP Addr 2 | -Entity ID (FQDN): |
| | -TCP Port 1 | | -TCP Port 2 | ôgtwy1.foo.comö |
| +-----+ +-----+ +-----+ +-----+ -Protocol: iFCP |
| | | | | |
| +-----+ +---------------+ +----------------------+ |
| +-----+ +---------------+ +-------------+ +------+ |
| | | | | | | |
| +-----+ +-----+ +----+ +------+ +----+ +------+ |
| |STORAGE NODE | |STORAGE NODE | |STORAGE NODE | |
| | -WWPN 1 | | -WWPN 2 | | -WWPN 3 | |
| | -Port ID 1 | | -Port ID 2 | | -Port ID 3 | |
| | -FWWN 1 | | -FWWN 2 | | -FWWN 3 | |
| | -FC COS | | -FC COS | | -FC COS | |
| +------+------+ +-------+-----+ +----+--------+ |
+--------|-------------------|------------|--------------+
| | |
+------+------+ +---+------------+---+
| FC DEVICE | | FC DEVICE |
| -WWNN 1 | | -WWNN 2 |
| | | |
+-------------+ +--------------------+
5.2.5 Required Commands and Response Messages for Support of iFCP
The iSNSP messages and responses displayed in the following tables
are available to support iFCP gateways. Messages indicated in the
REQUIRED TO IMPLEMENT column MUST be supported by the iSNS server
used by iFCP gateways. Messages indicated in the REQUIRED TO USE
column MUST be supported by the iFCP gateways themselves.
Gibbons, Tseng, Monia Standards Track 25
iSNS June 2001
REQUIRED TO:
Message Description Abbreviation Func ID Implement Use
------------------- ------------ ------- --------- ---
Register Dev Attr Req RegDevAttr 0x0001 * *
Dev Attr Query Request DevAttrQry 0x0002 * *
Dev Get Next Request DevGetNext 0x0003 *
Deregister Dev Request DeregDev 0x0004 * *
SCN Register Request SCNReg 0x0005 *
SCN Deregister Request SCNDereg 0x0006 *
SCN Event SCNEvent 0x0007 *
State Change Notification SCN 0x0008 *
DD Register DDReg 0x0009 * *
DD Deregister DDDereg 0x000A * *
DDS Register DDSReg 0x000B * *
DDS Deregister DDSDereg 0x000C * *
Entity Status Inquiry ESI 0x000D *
Name Service Heartbeat Heartbeat 0x000E *
Reserved Reserved 0x000F-0x0010
Request Switch ID RqstSwId 0x0011
Release Switch ID RlseSwId 0x0012
Get Switch IDs GetSwIds 0x0013
RESERVED 0x0014-0x00FF
Vendor Specific 0x0100-0x01FF
RESERVED 0x0200-0x8000
The following are iSNSP response messages in support of iFCP:
REQUIRED TO:
Response Message Desc Abbreviation Func_ID Implement Use
--------------------- ------------ ------- --------- ---
Register Dev Attr Rsp RegDevRsp 0x8001 * *
Dev Attr Query Resp DevAttrQryRsp 0x8002 * *
Dev Get Next Resp DevGetNextRsp 0x8003 *
Deregister Dev Resp DeregDevRsp 0x8004 * *
SCN Register Resp SCNRegRsp 0x8005 *
SCN Deregister Resp SCNDeregRsp 0x8006 *
SCN Event Resp SCNEventRsp 0x8007 *
SCN Response SCNRsp 0x8008 *
DD Register Rsp DDRegRsp 0x8009 * *
DD Deregister Rsp DDDeregRsp 0x800A * *
DDS Register Rsp DDSRegRsp 0x800B * *
DDS Deregister Rsp DDSDeregRsp 0x800C * *
Entity Stat Inquiry Resp ESIRsp 0x800D *
NOT USED 0x800E
RESERVED 0x800F-0x8010
Request Switch ID Resp RqstSwIdRsp 0x8011
Release Switch ID Resp RlseSwIdRsp 0x8012
Get Switch IDs GetSwIdRsp 0x0013
RESERVED 0x8014-0x80FF
Vendor Specific 0x8100-0x81FF
RESERVED 0x8200-0xFFFF
5.3 Attribute Descriptions for Discovery Domain Registration
Gibbons, Tseng, Monia Standards Track 26
iSNS June 2001
Discovery Domains are logical groupings of initiators and targets
that are used to limit the login process to the appropriate subset
of devices registered in the iSNS.
Support for Discovery Domains is required for all protocols. The
iSNS attributes for Discovery Domain, and Discovery Domain Set,
registration are shown in the following figure:
DISCOVERY DOMAIN SET
|
- DD Set_ID
- DD Set_Symbolic Name
- DD Set Enabled/Disabled
DD SET_MEMBER
|
- DD Set_ID
- DD_ID
DISCOVERY DOMAIN
|
- DD_ID
- DD_Symbolic Name
DD_MEMBER
|
- DD_ID
- Entity Identifier, iSCSI Name, or WWPN
Members of a Discovery Domain can be defined by registering one of
the following storage entity attributes in a Discovery Domain:
- iSCSI Name : this places the individual iSCSI
storage node in the Discovery Domain
- WWPN : this places the iFCP Storage Node in the
Discovery Domain
5.4 Use of TCP For iSNS Communication
TCP can be used for all iSNS communication. The iSNS server SHALL
accept TCP connections for client registrations. The TCP port used
by the iSNS server to receive TCP messages used SHALL be <<TBD>>.
The client can also use multiple streams to register attributes and
communicate with the server.
To register for ESI monitoring using TCP, the client SHALL register
the Portal ESI Interval using the TCP connection that will be used
to receive ESI inquiry messages.
To register for SCN notifications using TCP, the client SHALL
register the iSCSI/iFCP SCN Bitmap using the TCP connection that
SHALL be used to receive SCN notification messages.
Gibbons, Tseng, Monia Standards Track 27
iSNS June 2001
This allows the client to be flexible about how many and which
connections will be used for each feature. Using the above method,
a client can optionally open one stream and use it for SCN, ESI, and
iSNS queries. A client may also open up 3 sessions: one for ESI,
one for SCN, and another for iSNS queries.
If a TCP connection supporting ESI or SCN messages goes down, and
the client creates a new connection for the ESI or SCN messages,
then the client must reregister for ESI's and/or SCN's on the new
connection.
5.5 Use of UDP For iSNS Communication
The iSNS server MAY accept UDP messages for client registrations.
The iSNS server SHALL accept registrations from clients requesting
UDP-based ESI and SCN messages. The UDP port used to receive
messages SHALL be <<TBD>>.
To register for UDP-based ESI monitoring messages, the client SHALL
register the Portal ESI/SCN UDP Port to be used for communication of
ESI messages from the server to the client.
To register for UDP-based SCN notifications messages, the client
SHALL register at least one Portal ESI/SCN UDP port to be used for
communication of SCN messages from the server to the client. If an
entity has multiple Portals with registered ESI/SCN UDP Ports, then
ESI and SCN messages SHALL be delivered to each Portal registered to
receive such messages.
6. iSNS Message Attributes
When an iSNS client registers with the iSNS server, it provides
attribute values to describe the entity characteristics and
capabilities. The iSNS server also returns the attributes in
response to queries.
6.1 iSNS Attribute Summary
The following table lists all iSNSP message attributes for device
registration and queries:
T Entity Attributes Length Tag Reg Key Query Key
- ----------------------- ------ --- ------- -----------
Delimiter 0-256 0 N/A N/A
^ Entity Identifier (EID) 0-256 1 1|@ @|1|2|16,17|32|64
& Entity Protocol 4 2 1 @|1|2|16,17|32|64
Mgt IP Address 16 3 1 @|1|2|16,17|32|64
= Timestamp 8 4 1 @|1|2|16,17|32|64
Protocol Version Range 4 5 1 @|1|2|16,17|32|64
Registration Period 4 6 1 @|1|2|16,17|32|64
Gibbons, Tseng, Monia Standards Track 28
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* Entity Certificate var 15 1 @|1|2|16,17|32|64
# Portal IP-Address 16 16 1 @|1|16,17|32|64
$ Portal TCP/UDP Port 4 17 1 @|1|16,17|32|64
Portal Symbolic Name 0-256 18 16,17 @|1|16,17|32|64
ESI Interval 4 19 16,17 @|1|16,17|32|64
ESI/SCN UDP Port 4 20 16,17 @|1|16,17|32|64
Portal Group 4 21 16,17 @|1|16,17|32|64
* Portal Certificate var 31 16,17 @|1|16,17|32|64
# iSCSI Name 4-256 32 1% @|1|16,17|32|33
& iSCSI Node Type 4 33 32 @|1|16,17|32
Alias 0-256 34 32 @|1|16,17|32
iSCSI SCN Bitmap 4 35 32 @|1|16,17|32
* iSCSI Node Certificate var 40 32 @|1|16,17|32
# iFCP Node WWPN 8 64 1% @|1|16,17|64|66|96|128
Port_ID 4 65 64 @|1|16,17|64
Port_Type 4 66 64 @|1|16,17|64
Port_Symbolic Name 0-256 67 64 @|1|16,17|64
FC Fabric Port Name 8 68 64 @|1|16,17|64
FC Hard Address 4 69 64 @|1|16,17|64
FC Port IP-Address 16 70 64 @|1|16,17|64
FC Class of Service 4 71 64 @|1|16,17|64
FC FC-4 Types 32 72 64 @|1|16,17|64
FC FC-4 Descriptor 0-256 73 64 @|1|16,17|64
FC FC-4 Features 128 74 64 @|1|16,17|64
iFCP Node SCN bitmap 4 75 32 @|1|16,17|64
* iFCP Node Certificate var 80 64 @|1|16,17|64
iFCP Node Type 4 81 64 @|1|16,17|64
FC-4 Type Code 4 95 Query Key only
# FC Device WWNN 8 96 @ @|64|96
FC Device Sym Node Name 0-256 97 96 @|64|96
FC Device IP-Address 16 98 96 @|64|96
FC Device IPA 8 99 96 @|64|96
* FC Device Certificate var 100 96 @|64|96
Preferred ID 4 128 Switch ID msgs only
Assigned ID 4 129 Switch ID msgs only
Space_Identifier 0-256 130 Switch ID msgs only
RESERVED for iSNS server-specific tags in range 131-255
Company OUI 4 256
* Vendor-Spec iSNS Srvr var - tags in range 257-383
* Vendor-Spec Entity var - tags in range 384-511
* Vendor-Spec Portal var - tags in range 512-639
* Vendor-Spec iSCSI Node var - tags in range 640-767
* Vendor-Spec iFCP Node var - tags in range 768-895
* Vendor-Spec iFCP FC Node var - tags in range 896-1023
* Vendor-Specific DD var - tags in range 1024-1279
* Other Vendor-Specific var - tags in the range 1280-2047
RESERVED 2048-65535
The following is a description of the columns used in the above
table:
Attribute Type (T)
--------------------------------------------------------------
# : Required key for object registration.
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^ : Required key for object registration, unique value is
assigned by the iSNS if value not provided during initial
registration.
$ : Required as part of the key, and the canonical value is
used if one is not registered.
& : Attribute required during initial registration that is
not a key.
* : Optional to implement in the iSNS.
= : Cannot be used as a query key or be explicitly registered. The
value is assigned by the iSNS at registration / update.
@ : if no key is present then a new entry is created, or all
entries of the operating attributes are returned.
| : used to separate the different sets of possible keys in the
table.
% : If an iSCSI Name or iFCP Node WWPN is registered
without an EID key, then an Entity will be created and an EID
assigned. The assigned EID will be returned in the response
as an Operating attribute.
Length - indicates the attribute length. Variable-length
identifiers are NULL character terminated, which is included in the
length.
Tag - the integer tag value used to identify the attribute. All
undefined tag values are reserved.
Value û a description of the data.
Implementation Notes:
--------------------------------------------------------------
A well-formed registration contains the key of the object to
register, or no key if it can be generated by the iSNS. If an
attribute is present as a key, then it cannot be an operating
attribute.
The registration response will contain the key for each object
registered, including any key values that were assigned by the iSNS
as part of the registration. For example, if an entity, two
portals, and one iFCP node was registered, then the response message
key attributes section would contain the keys for each. The key
attributes, returned in the response, may be in a different order
they appeared in the registration.
iSNS client attributes are defined below.
6.2 Entity Identifier-Keyed Attributes
The following attributes are registered in the iSNS using the Entity
Identifier attribute as the key.
6.2.1 Entity Identifier (EID)
The Entity Identifier is a variable length identifier that uniquely
identifies each network entity registered in the iSNS. The
Gibbons, Tseng, Monia Standards Track 30
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attribute length varies from 4 to 256 bytes, and is a unique value
within the iSNS.
If the iSNS client does not provide an EID during registration the
iSNS shall generate one that is unique within the iSNS. If an EID
is to be generated, then the EID attribute value in the registration
message shall be empty (0 length). The generated EID shall be
returned in the registration response.
By convention, iSNS generated EIDs begin with the string ôiSNS:ö.
If an EID is registered by a client beginning with the string
ôiSNS:ö, then the iSNS server SHALL not assign the value to another
entity.
6.2.2 Entity Protocol
Entity Protocol is a required 4-byte attribute that indicates the
protocol of network entity that is being registered and is provided
by the iSNS client. The valid types are defined as below:
Type Value Entity Type
---------_ -----------
1 iSCSI
2 iFCP
All Others RESERVED
6.2.3 Management IP Address
This optional field is provided by the iSNS client. It contains the
IP Address used to manage the entity. The Management IP Address is
a 16-byte field that may contain either a 32-bit IPv4 or 128-bit
IPv6 address. When this field contains an IPv4 value, the most
significant 12 bytes are set to 0x00. If the network entity is
capable of being managed and this field is not set, then in-band
management is assumed.
6.2.4 Entity Registration Timestamp
This field is updated by the iSNS. It cannot be used as a query key
or be explicitly registered. It indicates the time the entity
registration occurred, an associated object was updated, or the time
of the most recent response to an Entity Status Inquiry message,
whichever is later. The time format is, in seconds, the update
period since the standard base time of 00:00:00 GMT on January 1,
1970.
6.2.5 Protocol Version Range
This optional field is provided by the iSNS client. This field
contains the minimum and maximum version of the protocol supported
by the entity. The most significant two bytes contain the maximum
version supported, and the least significant two bytes contain the
minimum version supported. If a range is not registered then the
entity is assumed to support all versions of the protocol.
Gibbons, Tseng, Monia Standards Track 31
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6.2.6 Registration Period
This required field, provided by the iSNS client, indicates the
maximum period, in seconds, that the entity registration will be
maintained by the server without an update or ESI response from the
client. If the Registration Period is set to 0, then the Entity
SHALL NOT be deregistered as a result of no update messages from the
client.
To refresh the registration, the iSNS client may perform a re-
registration with the update flag set, which updates any field of
the registration.
Byte 0 and 1 represents the entity registration period, in seconds.
Byte 2 and 3 are reserved.
If ESI support is requested as part of a portal registration, the
ESI Response message received by the server SHALL act as an
alternative to an update of the entity registration.
If ESI messages are not requested by an entity and the Registration
Period is not set to 0, then the entity registration SHALL be
removed if the client does not update the registration before the
registration period has expired.
6.2.7 Entity Certificate
This attribute contains an X.509 certificate that is bound to the
NETWORK ENTITY of the iSNS client. This certificate is uploaded and
registered to the iSNS by clients wishing to allow other clients to
authenticate themselves and access the services offered by that
NETWORK ENTITY. This certificate MAY also be used to set up the TLS
association between the iSNS client and server, as well as to key
the authentication block in the iSNSP. The maximum size of this
variable length field is implementation dependent.
6.3 Portal-Keyed Attributes
The following portal attributes are registered in the iSNS using the
combined Portal IP-Address and Portal TCP/UDP Port as the key. Each
portal is associated with one Entity Identifier object key.
6.3.1 Portal IP-Address
The IP address of the PORTAL through which a STORAGE NODE can
transmit and receive storage data. This required field is provided
by the iSNS client. When an IPv4 value is contained in this field,
the most significant 12 bytes are set to 0x00. The Portal IP
Address along with the Portal TCP/UDP Port number uniquely
identifies a Portal.
6.3.2 Portal TCP/UDP Port
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The TCP/UDP port of the PORTAL through which a STORAGE NODE can
transmit and receive storage data. This required 4 byte field is
provided by the iSNS client. Bit 0 to 15 represents the TCP/UDP
port number. Bit 16 represents the port type. If bit 16 is set the
port type is UDP. Otherwise it is TCP. Bits 17 to 31 are reserved.
If the field value is 0, then the port number is the implied
canonical port number and type of the protocol indicated by the
associated Entity Protocol.
The Portal IP-Address along with the Portal TCP/UDP Port number
uniquely identifies a Portal.
6.3.3 Portal Symbolic Name
This is an optional, variable-length text-based value from 0 to 256
bytes. The text field contains user-readable UTF-8 text, and is
terminated with at least one NULL character. The Portal Symbolic
Name is a user-readable description of the Portal entry in the iSNS.
6.3.4 Entity Status Inquiry Interval
This optional field is provided by the iSNS client. It indicates
the minimum time, in seconds, between Entity Status Inquiry (ESI)
messages sent from the iSNS to this entity portal. ESI messages can
be used to verify that a Portal registration continues to be valid.
To request monitoring by the iSNS, an iSNS client registers a non-
zero value for this portal attribute using a RegDevAttr message.
If the iSNS does not receive an ESI response message from a Portal
after having sent no more than three ESI messages, then the Portal
SHALL be deregistered.
If all Portals associated with an entity that have registered for
ESI messages are deregistered due to non-response, then the entity
SHALL be deregistered.
If the iSNS is unable to support ESI messages, it SHALL reject the
ESI request by returning an "ESI Not Available" error code. The
rejection might occur in situations where the resulting frequency of
ESI messages being issued to clients would pass an implementation-
specific threshold.
6.3.5 ESI/SCN UDP Port
This optional field is provided by the iSNS client. If the client
requires UDP based ESI monitoring or SCN notification, it SHALL
register the UDP port to be used for communication from the server
to a client Portal. Bit 0 to 15 represents the UDP port number.
Bits 16 to 31 are reserved.
If an entity node registers for SCN notifications with a UDP
message, at least one entity portal shall have a registered ESI/SCN
UDP port number. The iSNS server will return an error for an SCN
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registration if no ESI/SCN port has been registered. If multiple
Portals have a registered ESI/SCN UDP port, then SCN data MAY be
delivered to any of the available registered portals.
6.3.6 Portal Group
This optional field is provided by the iSNS client. The Portal
Group is used to group portals into aggregation groups. All entity
portals that belong to the same Portal Group can provide connections
to the same STORAGE NODE. This allows multiple sessions to be
established to a node through multiple portals. The least
significant two bytes contain the Portal Group for the Portal. The
most significant two bytes are reserved.
6.3.7 Portal Certificate
This attribute contains an X.509 certificate that is bound to the
PORTAL of the iSNS client. This certificate is used to identify and
authenticate communications to the IP address supported by the
Portal. This certificate MAY be used to set up the authenticating SA
supporting the authentication block for iSNSP messages originated
from the Portal IP Address.
6.4 iSCSI Node-Keyed Attributes
The following attributes are registered in the iSNS using the iSCSI
Name attribute as the key. Each set of Node-Keyed attributes is
associated with one Entity Identifier object key.
Although the iSCSI Name key is associated with one Entity
Identifier, it is unique across the entire iSNS.
6.4.1 iSCSI Name
This identifier uniquely defines an iSCSI STORAGE NODE, and is a
variable-length text-based value from 0 to 256 bytes. This field is
required for iSCSI STORAGE NODEs, and is provided by the iSNS
client.
If an iSCSI Name is registered without an EID key, then an Entity
will be created and an EID assigned. The assigned EID will be
returned in the registration response as an operating attribute.
6.4.2 iSCSI Node Type
This required 32-bit field is a bitmap indicating the type of iSCSI
STORAGE NODE. The bit fields are defined below. An enabled bit
indicates the node has the corresponding characteristics.
Gibbons, Tseng, Monia Standards Track 34
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Bit Field Node Type
--------- ---------
0 (Lsb) Target
1 Initiator
2 Control
All Others RESERVED
If the 'Target' bit is set, then the node represents an iSCSI
target.
If the 'Initiator' bit is set, then the node represents an iSCSI
initiator.
If the control bit is set, then the node represents a gateway,
management station, or other device which is not an initiator or
target that requires the ability to send and receive iSNSP messages,
including state change notifications.
6.4.3 iSCSI Node Alias
This is an optional, variable-length text-based value from 0 to 256
bytes. The text field contains user-readable UTF-8 text, and is
terminated with at least one NULL character. The Alias is a user-
readable description of the node entry in the iSNS.
6.4.4 iSCSI Node SCN Bitmap
This optional field is provided by the iSNS client. It indicates
the events that the iSCSI Node is interested in. These events can
cause a State Change Notification (SCN) to be generated.
Bit Field Flag Description
--------- ----------------
0 CHANGE IN DD MEMBERSHIP
1 CHANGE IN NETWORK
2 CHANGE IN CLIENT REGISTRATION PARAMETERS
3 CLIENT ADDED
4 CLIENT REMOVED
All others reserved.
6.4.5 iSCSI Node Certificate
This optional attribute contains an X.509 certificate that is bound
to the iSCSI STORAGE NODE of the iSNS client. For example, this
X.509 certificate may have the Node Identifier of the target device.
This certificate is uploaded and registered to the iSNS by clients
wishing to allow other clients to authenticate themselves and access
the STORAGE NODE. This certificate SHOULD NOT be used to set up the
authenticating SA supporting the iSNSP authentication block.
6.5 iFCP Node-Keyed Attributes
The following attributes are registered in the iSNS using the iFCP
Node World Wide Port Name (WWPN) attribute as the key. Each set of
Gibbons, Tseng, Monia Standards Track 35
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iFCP Node-Keyed attributes is associated with one Entity Identifier
object key.
Although the iFCP Node WWPN is associated with one Entity
Identifier, it is globally unique.
6.5.1 iFCP Node Port Name (WWPN)
This 64-bit identifier uniquely defines the iFCP Node, and is the
World Wide Port Name (WWPN) of the corresponding Fibre Channel
device. This globally unique identifier is used during the device
registration process, and uses a value conforming to IEEE Naming
Assignment Authority (NAA) type 1, 2, 5, or 6. This format is found
in ANSI/IEEE Std 802-1990 [802-1990].
6.5.2 Port ID
Along with the IP Address, this field uniquely identifies a native
Fibre Channel device port in the network, and maps one-to-one to a
specific Port Name (WWPN) entry. The Port ID is used for iFCP based
storage devices.
6.5.3 Port Type
Indicates the type of iFCP node port. This is provided by the iSNS
client. Encoded values for this field are listed in the following
table:
Type Description
---- -----------
0x0000 Unidentified/Null Entry
0x0001 Fibre Channel N_Port
0x0002 Fibre Channel NL_Port
0x0003 Fibre Channel F/NL_Port
0x0004-0080 RESERVED
0x0081 Fibre Channel F_Port
0x0082 Fibre Channel FL_Port
0x0083 RESERVED
0x0084 Fibre Channel E_Port
0x0085-00FF RESERVED
0xFF11 mFCP Port
0xFF12 iFCP Port
0xFF13-FFFF RESERVED
6.5.4 iFCP Node Port Symbolic Name
A variable-length text-based description of up to 255 bytes, that is
associated with the iSNS-registered iFCP Node in the network. The
text field contains user-readable UTF-8 text and is terminated with
at least one NULL character. This optional field is normally
provided by the iSNS client during registration. However, network
management application can update this field as required.
Gibbons, Tseng, Monia Standards Track 36
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6.5.5 iFCP Node Fabric Port Name (FWWN)
This 64-bit identifier uniquely defines the fabric port. If the
iSNS client is attached to a Fibre Channel fabric port with a
registered Port Name, then that fabric Port Name shall be indicated
in this field. This field is included in the iSNSP for
compatibility with Fibre Channel fabric devices and topologies.
The Fabric Port may itself be registered as a port in the iSNS. In
that case, the Fabric Port Name (FWWN) attribute of fabric attached
ports will match the Port Name (WWPN) of the Fabric Port
registration.
6.5.6 FC Hard Address
This optional field is the requested hard address 24-bit NL Port
Identifier, included in the iSNSP for compatibility with Fibre
Channel Arbitrated Loop devices and topologies.
6.5.7 FC Port IP Address
The Fibre Channel IP address associated with the iFCP Node. This
optional field is included for compatibility with Fibre Channel.
When an IPv4 value is contained in this field, the most significant
12 bytes are set to 0x00. This value is provided by the iSNS
client.
6.5.8 FC Class of Service (COS)
This 32-bit bit-map field indicates the Fibre Channel COS types that
are supported by the registered port. This field is provided by a
Fibre Channel-based iSNS client. The COS values are equivalent to
Fibre Channel COS values. The valid COS types, and associated bit-
map, are listed in the following table:
Class of Service Description Bit-Map
---------------- ----------- ---------
2 Delivery Confirmation Provided bit 2 set
3 Delivery Confirmation Not Provided bit 3 set
RESERVED other
6.5.9 FC FC-4 Types
This 32-byte field indicates the FC-4 protocol types supported by
the associated port. This field for iFCP Node is provided by the
iSNS client. This field can be used to support Fibre Channel
devices and is consistent with FC-GS-4.
6.5.10 FC FC-4 Descriptor
A variable-length text-based description of up to 256 bytes, that is
associated with the iSNS-registered device port in the network.
This optional field for iFCP ports is provided by the iSNS client.
This field can be used to support Fibre Channel devices. This field
Gibbons, Tseng, Monia Standards Track 37
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can be used to support Fibre Channel devices and is consistent with
FC-GS-4.
6.5.11 FC FC-4 Features
This is a 128-byte array, 4 bits per type, for the FC-4 protocol
types supported by the associated port. This optional field for
iFCP ports is provided by the iSNS client. This field can be used
to support Fibre Channel devices and is consistent with FC-GS-4.
6.5.12 iFCP Node SCN Bitmap
This optional field is provided by the iSNS client. It indicates
the events that the iFCP Node is interested in. These events can
cause SCN to be generated.
Bit Field Flag Description
--------- ----------------
0 CHANGE IN DD MEMBERSHIP
1 CHANGE IN NETWORK
2 CHANGE IN CLIENT REGISTRATION PARAMETERS
3 CLIENT ADDED
4 CLIENT REMOVED
All others reserved.
6.5.13 iFCP Node Certificate
This optional attribute contains an X.509 certificate that is bound
to the iFCP STORAGE NODE of the iSNS client. For example, this
X.509 certificate may have the Node Identifier of the target device.
This certificate is uploaded and registered to the iSNS by clients
wishing to allow other clients to authenticate themselves and access
the STORAGE NODE. This certificate SHOULD NOT be used to set up the
authenticating SA supporting the iSNSP authentication block.
6.5.14 iFCP Node Type
This required 32-bit field is a bitmap indicating the type of iFCP
STORAGE NODE. The bit fields are defined below. An enabled bit
indicates the node has the corresponding characteristics.
Bit Field Node Type
--------- ---------
0 (Lsb) Target
1 Initiator
2 Control
All Others RESERVED
6.6 iFCP FC Device Node-Keyed Attributes
The following attributes are registered in the iSNS using the iFCP
FC Node World Wide Node Name (WWNN) attribute as the key. Each set
of iFCP FC Node-Keyed attributes represents a single device, and can
be associated with many iFCP Node Ports.
Gibbons, Tseng, Monia Standards Track 38
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The iFCP Node WWNN is unique across the entire iSNS.
6.6.1 iFCP FC Device Node Name (WWNN)
Node Name is a 64-bit identifier that uniquely identifies the iFCP
FC device node in the network, and is the World Wide Node Name
(WWNN) of the corresponding Fibre Channel device. This globally
unique identifier is used during the device registration process,
and uses a value conforming to IEEE Naming Assignment Authority
(NAA) type 1, 2, 5, or 6. This format is found in ANSI/IEEE Std
802-1990 [802-1990].
6.6.2 iFCP FC Device Symbolic Name
A variable-length text-based description of up to 256 bytes, that is
associated with the iSNS-registered FC Device in the network. The
text field contains user-readable UTF-8 text and is terminated with
at least one NULL character. This optional field is normally
provided by the iSNS client during registration. However, network
management application can update this field as required.
6.6.3 FC Device IP Address
This optional IP address is associated with the device node in the
network. This field is included for compatibility with Fibre
Channel. When an IPv4 value is contained in this field, the most
significant 12 bytes are set to 0x00. This value is provided by the
iSNS client.
6.6.4 FC Device IPA
This optional 8 byte Fibre Channel Initial Process Associator (IPA)
is associated with the device node in the network. This field is
included for compatibility with Fibre Channel, and is provided by a
Fibre Channel-based iSNS client entity. The initial process
associator can be used for communication between Fibre Channel
devices.
6.6.5 FC Device Certificate
This optional attribute contains an X.509 certificate that is bound
to the FC DEVICE of the iSNS client.
6.7 Other Attributes
The following are not attributes of the previously-defined objects.
6.7.1 FC-4 Type Code
This is a 4-byte field, and is used to provide a FC-4 type during a
FC-4 Type query. The FC-4 types are consistent with the FC-4 Types
as defined in FC-PH. Byte 0 contains the FC-4 type. All other
bytes are reserved.
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6.7.2 Preferred ID
This is a 4-byte unsigned integer field, and is the requested value
that the iSNS client wishes to use for the SWITCH_ID. The iSNS
server SHALL grant the iSNS client the use of the requested value as
the SWITCH_ID, if the requested value has not been already
allocated. If the requested value is not available, the iSNS server
SHALL return a different value that has not been allocated.
6.7.3 Assigned ID
This is a 4-byte unsigned integer field that is used to support iFCP
Transparent Mode. When operating in iFCP Transparent Mode, the
RqstSwId message SHALL be used by each iFCP gateway to reserve its
own unique SWITCH_ID value from the range 1 to 239. When a Switch
ID is no longer required, it SHALL be released by the iFCP gateway
using the RlseSwId message. The iSNS MAY use the Entity Status
Inquiry message to determine if an iFCP gateway is still present on
the network.
6.7.4 Space_Identifier
This is a UTF-8 encoded string. The Space_Identifier string is used
as a key attribute to identify a range of non-overlapping SWITCH_ID
values to be allocated using RqstSwId. Each Space_Identifier string
submitted by iSNS clients shall have its own range of non-
overlapping SWITCH_ID values to be allocated to iSNS clients.
6.8 Discovery Domain Registration Attributes
iSNS STORAGE NODE objects can be placed into Discovery Domains.
Only objects that share the same enabled Discovery Domain can query
for information about each other. Discovery Domains can overlap, so
an iSCSI node may be a member of many DDÆs.
Enabled Discovery Domains are members of one or more enabled
Discovery Domain Sets (DDS). Discovery Domains that are not members
of at least one enabled DDS are disabled. Therefore, Discovery
Domains are not directly enabled, but rather are enabled through
their association with one or more enabled Discovery Domain Sets
(DDS). Discovery Domain Sets are enabled by setting bit 0 in the DDS
Status field.
6.8.1 iSNS Discovery Domain Attribute Summary
The following table lists the iSNSP DD attributes:
Gibbons, Tseng, Monia Standards Track 40
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Attribute Name Size(bytes) ID Reg Key Query Key
-------------- ----------- -- ------- ---------
DD_Set ID 4 101 @ 1,32,64,101,104
DD_Set Sym Name 4-256 102 101 101
DD_Set Status 4 103 101 101
DD_ID 4 104 @|101* 1,32,64,101,104
DD_Symbolic Name 4-256 105 104 104
DD_iSCSI Node Member 0-256 107 104 104
DD_iFCP Member (WWPN) 8 108 104 104
@ = no key required during registration
| = either key can be used during registration
* = When a DD ID is placed into a DD Set by using the DDS ID
as a key
All undefined tag values are reserved.
6.8.2 DD Set ID Keyed Attributes
6.8.2.1 Discovery Domain Set ID (DDS ID)
The DDS ID is a unique integer identifier used in the iSNS directory
database to indicate a Discovery Domain Set. A DDS is a collection
of Discovery Domains that can be enabled or disabled by a management
station. This value is used as a key for DDS attribute queries.
When a Discovery Domain is registered it is initially not in any
DDS.
If the iSNS client does not provide a DDS_ID in a DDS registration
request message, the iSNS shall generate a DDS_ID value that is
unique within the iSNS database for that new DDS. The created DDS
ID shall be returned in the response message. The DDS ID value of 0
is reserved.
6.8.2.2 Discovery Domain Set Symbolic Name
The DDS_Symbolic Name is a UTF-8, variable-length, NULL-terminated
string. This is an user-readable field used to assist a network
administrator in tracking the DDS function. When registered by a
client, the DDS symbolic name SHALL be verified unique by the iSNS.
If the DDS symbolic name is not unique, then the DDS registration
SHALL be rejected with an ôInvalid Registrationö error code. The
invalid attribute(s), in this case the DDS symbolic name, SHALL be
included in the response.
6.8.2.3 Discovery Domain Set Status
The DDS_Status field is a 32-bit bitmap indicating the status of the
DDS. Bit 0 of the bitmap indicates whether the DDS is Enabled (1)
or Disabled (0). The default value for the DDS Enabled flag is
Disabled (0).
Gibbons, Tseng, Monia Standards Track 41
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Bit Field DDS Status
--------- ---------
0 (Lsb) DDS Enabled (1) / DDS Disabled (0)
All Others RESERVED
6.8.2.4 Discovery Domain Set Member
The Discovery Domain Set Member is a DD ID for a previously
registered Discovery Domain. The DD ID tag value is used to
represents membership.
6.8.3 DD ID Keyed Attributes
6.8.3.1 Discovery Domain ID (DD ID)
The DD ID is a unique identifier used in the iSNS directory database
to indicate the DD. This value is used as the key for any DD
attribute query. If the iSNS client does not provide a DD_ID in a DD
registration request message, the iSNS shall generate a DD_ID value
that is unique within the iSNS database for that new DD (i.e., the
iSNS client will be registered in a new DD). The created DD ID
shall be returned in the response message. The DD ID value of 0 is
reserved.
6.8.3.2 Discovery Domain Symbolic Name
The DD_Symbolic Name is a UTF-8 encoded, variable-length, NULL-
terminated string. When registered by a client, the DD symbolic
name SHALL be verified unique by the iSNS. If the DD symbolic name
is not unique, then the DD registration SHALL be rejected with an
ôInvalid Registrationö error code. The invalid attribute(s), in
this case the DD symbolic name, SHALL be included in the response.
6.8.3.3 Discovery Domain iSCSI Node Member
The iSCSI Name of an iSNS client that is a member of the DD. The DD
may have a list of 0 to n members. The iSCSI Name of the iSNS
client represents membership.
6.8.2.4 Discovery Domain iFCP Node Member
The iFCP Node Port Name of an iSNS client that is a member of the
DD. The DD may have a list of 0 to n members. Membership is
represented by the iFCP Node Port Name (WWPN) of the iSNS client
being listed.
6.9 Vendor-Specific Attributes
Specific iSNS implementations MAY define vendor-specific attributes
for private use. The tag values reserved for vendor-specific and
user-specific use are defined in section 6.1. To avoid
misinterpreting proprietary attributes, it is RECOMMENDED that the
vendor's own OUI (Organizationally Unique Identifier) be placed in
the upper three bytes of the attribute field itself. If the OUI is
Gibbons, Tseng, Monia Standards Track 42
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not used, then some other unique marker recognizable by the vendor
SHOULD be used. The OUI is defined in IEEE Std 802-1990, and is the
same constant used to generate 48 bit Universal LAN MAC addresses.
A vendor's own iSNS implementation will then be able to recognize
the OUI in the vendor-specific or user-specific attribute field, and
be able to execute vendor-specific handling of the attribute.
6.10 Company OUI
This attribute is the OUI (Organizationally Unique Identifier)
identifying the specific vendor implementing the iSNS. It is used
to identify the original creator of a vendor-specific iSNSP message.
7. iSNSP Message Format
The iSNSP message format is similar to the format of other common
protocols such as DHCP, DNS and BOOTP. An iSNSP message may be sent
in one or more iSNS Protocol Data Units (PDU). Each PDU is 4 byte
aligned. The following describes the format of the iSNSP PDU:
Byte MSb LSb
Offset 31 0
+---------------------+----------------------+
0 | iSNSP VERSION | FUNCTION ID | 4 Bytes
+---------------------+----------------------+
4 | PDU LENGTH | FLAGS | 4 Bytes
+---------------------+----------------------+
8 | TRANSACTION ID | SEQUENCE ID | 4 Bytes
+---------------------+----------------------+
12 | |
| PDU PAYLOAD | N Bytes
| ... |
+--------------------------------------------+
12 + N | AUTHENTICATION BLOCK (if present) | L Bytes
+--------------------------------------------+
Total Length = 12 + N
7.1 iSNSP PDU Header
The iSNSP header contains the iSNSP VERSION, FUNCTION ID, PDU
LENGTH, FLAGS, TRANSACTIONID, and SEQUENCE ID fields as defined
below.
7.1.1 iSNSP Version
The iSNSP version is currently 0x0001.
7.1.2 iSNSP Function ID
The FUNCTION ID defines the type of iSNS message and the function
the message is supporting. See section 5 under the appropriate
protocol (i.e., iSCSI or iFCP) for a mapping of the FUNCTION_ID
value to the iSNSP Command or Response message. All PDU's
Gibbons, Tseng, Monia Standards Track 43
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comprising an iSNSP message must have the same FUNCTION_ID and
TRANSACTION ID value.
7.1.3 iSNSP PDU Length
The iSNS PDU LENGTH specifies the length of the PDU PAYLOAD field in
bytes. The payload contains the data/attribute values for the
operation.
7.1.4 iSNSP Flags
The FLAGS field indicates additional information about the message
and the type of iSNS entity that generated the message. The
following table displays the valid flags:
Bit Field Enabled Means:
--------- -------------
0-9 RESERVED
10 First PDU of the iSNS message
11 Last PDU of the iSNS message
12 Update Flag (used only for registrations)
13 Authentication Block Present
14 Sender is the iSNS server
15 Sender is the iSNS client
7.1.5 iSNSP Transaction ID
The TRANSACTION ID is set to a unique random value for each request
message. Replies MUST use the same TRANSACTION ID value as the
associated iSNS request message. If a message is retransmitted, the
same TRANSACTION ID value MUST be used.
7.1.6 iSNSP Sequence ID
The SEQUENCE ID is set to a unique value for each PDU within a
single transaction. Each SEQUENCE_ID value in each PDU SHALL be
numbered sequentially in the order that the PDU's are transmitted.
If a message is retransmitted, then the same SEQUENCE_ID value MUST
be used for all PDU's in the message.
7.2 iSNSP Message Segmentation and Reassembly
iSNS messages may be carried in one or more iSNS PDU's. If only one
iSNS PDU is used to carry the iSNS message, then bit 10 (First PDU)
and bit 11 in the FLAGS field (Last PDU) SHALL both be enabled. If
multiple PDUs are used to carry the iSNS message, then bit 10 SHALL
be enabled in the first PDU of the message, and bit 11 SHALL be
enabled in the last PDU.
All PDU's comprising the same iSNSP message SHALL have the same
FUNCTION_ID and TRANSACTION_ID values. Each PDU comprising an iSNSP
message SHALL have a unique SEQUENCE_ID value.
Gibbons, Tseng, Monia Standards Track 44
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The authentication operation described in section 7.5 SHALL be
performed on a per-PDU basis.
7.3 iSNSP Message Payload
The MESSAGE PAYLOAD is variable length and contains attributes used
for registration and query operations. The attribute data items use
a format similar to other protocols, such as DHCP (RFC 2131)
options. Each iSNS attribute is specified in the iSNSP message
payload using Tag-Length-Value (TLV) data format, as shown below:
Byte MSb LSb
Offset 31 0
+--------------------------------------------+
0 | Attribute Tag | 4 Bytes
+--------------------------------------------+
4 | Attribute Length (N) | 4 Bytes
+--------------------------------------------+
8 | |
| Attribute Value | N Bytes
| |
+--------------------------------------------+
Total Length = 8 + N
Attribute Tag - a 4-byte tag field that identifies the attribute as
defined in section 6.1. This field contains the ID of the indicated
attribute.
Attribute Length - a 4-byte field that indicates the length, in
bytes, of the attribute value to follow.
Attribute Value - a variable-length field containing the attribute
value.
The above format is used to identify each attribute in the iSNS
message payload. Each iSNSP request message contains several
attributes in the above format to identify the requesting iSNS
client and register or query for attribute values in the iSNS
server.
7.3.1 Attribute Value 4-Byte Alignment
All attribute values are aligned at 4 byte boundaries. For variable
length attributes, the value length is increased to the next 4-byte
boundary and the value is NULL padded.
7.4 iSNSP Response Error Codes
All iSNSP response messages contain a 4-byte ERROR CODE field as the
first field in the iSNSP PAYLOAD. If the original iSNSP request
message was processed normally by the iSNS server, or the iSNS
client for ESI and SCN messages, the field SHALL contain 0x00000000
(NO ERROR).
Gibbons, Tseng, Monia Standards Track 45
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Error Code Error Description
---------- -----------------
0 No Error
1 Unknown Error
2 Message Format Error
3 Invalid Registration
4 Requested ESI Period Too Short
5 Invalid Query
6 Authentication Unknown
7 Authentication Absent
8 Authentication Failed
9 No Such Entry
10 Version Not Supported
11 Internal Bus Error
12 Busy Now
13 Option Not Understood
14 Invalid Update
15 Message Not Supported
16 SCN Event Rejected
17 SCN Registration Rejected
18 Attribute not Implemented
19 SWITCH_ID not available
20 SWITCH_ID not allocated
21 ESI Not Available
22 And Above RESERVED
All undefined Error Code values are RESERVED.
7.5 Message Authentication
iSNSP provides an optional PDU authentication capability. Network
interactions using iSNSP occur in short transactions, and are
generally not session based. The iSNS client connects to the iSNS
server only when information needs to be registered or queried. The
authentication mechanism described here is compatible with that used
in Service Location Protocol version 2 [RFC2608].
Public Key Encryption MAY be used for message authentication. If a
public key infrastructure is not available, a shared secret
algorithm MAY alternatively be used. A shared secret mechanism may
leverage a Kerberos server, or may involve manual distribution of a
private key to the iSNS server and each iSNS client.
If a PKI is available with an X.509 certificate authority, then
public key authentication of clients is possible. The
authentication block leverages the DSA with SHA-1 algorithm, which
can easily integrate into a public key infrastructure.
The SNSP optional authentication block is a digital signature for
the iSNSP PDU. The digital signature is calculated on a per-PDU
basis. The authentication block contains the following information:
1. A time stamp, to prevent replay attacks
2. A structured authenticator containing a signature calculated
Gibbons, Tseng, Monia Standards Track 46
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over the time stamp and the message being secured
3. An indicator of the cryptographic algorithm that was used to
calculate the signature.
4. An indicator of the keying material and algorithm parameters,
used to calculate the signature.
The authentication block is described in the following figure:
Byte MSb LSb
Offset 7 6 5 4 3 2 1 0
+----------------------------------+
0 | BLOCK STRUCTURE DESCRIPTOR | 2 Bytes
+----------------------------------+
2 | AUTHENTICATION BLOCK LENGTH | 2 Bytes
+----------------------------------+
4 | TIMESTAMP | 4 Bytes
+----------------------------------+
8 | SPI STRING LENGTH | 1 Byte
+----------------------------------+
9 | SPI STRING | N Bytes
+----------------------------------+
9 + N | STRUCTURED AUTHENTICATOR | M Bytes
+----------------------------------+
Total Length = 9 + N + M
BLOCK STRUCTURE DESCRIPTOR (BSD) - Defines the structure and
algorithm to use for the STRUCTURED AUTHENTICATOR. Currently, the
only defined value for BSD is 0x0002, which represents DSA with SHA-
1. Details on DSA can be found in [DSS]. BSD values from 0x0000 to
0x7FFF are assigned by IANA, while 0x8000 to 0x8FFF are for private
use. The BSD value 0x0002 is compatible with the X.509 PKI
specification, allowing easy integration of the STRUCTURED
AUTHENTICATOR format with an existing PKI infrastructure.
AUTHENTICATION BLOCK LENGTH - Defines the length of the
authentication block, beginning with the BSD field and running
through the last byte of the STRUCTURED AUTHENTICATOR.
TIMESTAMP - This is a 4-byte unsigned, fixed-point integer giving
the number of seconds since 00:00:00 GMT on January 1, 1970.
SPI STRING LENGTH - The length of the SPI STRING field.
SPI STRING (Security Parameters Index) - Index to the key and
algorithm used by the message recipient to decode the STRUCTURED
AUTHENTICATOR field.
STRUCTURED AUTHENTICATOR - Contains the digital signature. For the
default BSD value of 0x0002, this field contains the binary ASN.1
encoding of output values from the DSA with SHA-1 signature
calculation.
7.6 Registration and Query Messages
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The iSNSP registration and query message payloads contain a list of
attributes, and have the following format:
MSb LSb
31 0
+----------------------------------------+
| Source Attribute (Query Only) |
+----------------------------------------+
| Key Attribute[1] (if present) |
+----------------------------------------+
| Key Attribute[2] (if present) |
+----------------------------------------+
| Key Attribute[3] (if present) |
+----------------------------------------+
| . . . |
+----------------------------------------+
| - Delimiter Attribute - |
+----------------------------------------+
| Operating Attribute[1] |
+----------------------------------------+
| Operating Attribute[2] (if present) |
+----------------------------------------+
| Operating Attribute[3] (if present) |
+----------------------------------------+
| . . . |
+----------------------------------------+
iSNS Registration and Query messages, sent by iSNS Clients, are sent
to the iSNS IP-Address and TCP/UDP Port. The iSNS Responses will be
sent to the iSNS Client IP-Address and the originating TCP/UDP Port
used for the associated registration and query message.
7.6.1 Source Attribute
The source attribute is used to identify the iSNS client to the iSNS
server for queries and other messages that require source
identification. The source attribute uniquely identifies the source
of the message. Valid source attribute types are shown below.
Gibbons, Tseng, Monia Standards Track 48
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Valid Source Attributes
-----------------------
iSCSI Name (iSCSI only)
iFCP Node Port WWN (iFCP only)
Delimiter Field (If Administratively Allowed)
For a query operation, the source attribute is used to bind the
scope into the Discovery Domains of which the source is a member.
The iSNS may validate that the Source Attribute matches client
certificate information. If the iSNS is validating Source Attribute
information, and the Source Attribute does not match the client
certificate, then the request will be rejected with an
authentication error code.
The Source Field MAY administratively be allowed to contain the
Delimiter Field (Tag of 0, Length of 0). If the Source Attribute is
the Delimiter Field, then the operation SHALL be performed on all
objects in the iSNS database without scoping to a Discovery Domain.
7.6.2 Key Attributes
Key attributes are used to identify the object (or objects) in the
iSNS server that the registration or query operation will be
performed on. The number of Key Attributes depends on the specific
iSNSP request or query operation being performed.
7.6.3 Delimiter Attribute
The Delimiter Attribute separates the key attributes from the
operating attributes in a message payload. The Delimiter Attribute
has a tag value of 0 and a length value of 0. The Delimiter
Attribute is effectively 8 Bytes long, a 4 Byte tag containing
0x00000000, and a 4 Byte length field containing 0x00000000.
7.6.4 Operating Attributes
The Operating Attributes are a list of one or more attributes
related to the actual iSNS registration or query operation being
performed. In a registration, operating attributes represent values
to be registered by the iSNS client performing the registration. In
a query, operating attributes represent values being requested by
the iSNS client.
The number of possible Operating Attributes depends on the specific
iSNSP request or query. For example, the Operating Attributes in a
Device Attribute Query message are the set of attributes to be
returned in the associated Device Attribute Query Response message
that match the Key Attributes of the query.
Some iSNSP messages do not require any Operating Attributes.
7.6.4.1 Operating Attributes for Query and Get Next Requests
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In Query and Get Next request messages, TLV attributes with length
value of 0 are used to indicate what operating attributes are to be
returned in the corresponding response. Operating Attribute values
which match the TLV attributes in the original message are returned
in the response message.
7.6.5 Registration and Query Message Types
The following describes each query and message type.
7.6.5.1 Register Device Attribute Request (RegDevAttr)
The RegDevAttr message type is 0x0001. The RegDevAttr message
provides an iSNS client with the means to register network entities.
The iSNS client formulates a RegDevAttr by specifying Key
Attribute(s) and list of Operating Attributes to register. All
values are in Tag Length Value (TLV) format.
Attributes following the Delimiter Attribute are Operating
Attributes. Depending on the setting of the Update bit in the FLAGS
field, the Operating attribute values in the RegDevAttr message will
either replace existing attributes(s), or be added to existing
attributes(s). See section 7.6.5.1.1 below for a complete
description of the Update Flag.
The operating attributes are the elements that will be registered.
Multiple attributes can be registered in one RegDevAttr. The
ordering of the operating attributes indicates the associations to
be created in the iSNS. For example, Portal attributes following
Entity attributes SHALL create a link between the registered entity
and portal. Similarly, node attributes following entity attributes
will create an association.
A RegDevAttr message with no key attribute results in creation of a
new entity (EID) (in addition, the update flag MUST NOT be set). If
the EID attribute (with non-zero length) is included among the
operating attributes in the RegDevAttr message, then the new entity
SHALL be assigned the value contained in that EID attribute.
Otherwise, if the EID attribute is not contained among the operating
attributes of the RegDevAttr message, or if the EID is an operating
attribute with TLV length of 0, then the iSNS SHALL assign the EID
value that is returned in the RegDevAttr Response message.
Gibbons, Tseng, Monia Standards Track 50
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One RegDevAttr message can contain attributes for Entity, Portal,
and Node objects if each of these attributes are contained in the
same Entity. When the registration contains attributes for the
Entity, Portal, and Node objects together in the same message, then
the appropriate Portal, and Node key attributes must be registered
as part of the operating attributes.
Ordering of the attributes is important in multi-object
registrations. For example, Node Attributes follow a valid Node
key.
7.6.5.1.1 Update Flag
The Update Flag, contained in the message header FLAGS field,
indicates whether the registration message is an update to an
existing entry. If the Update bit in the FLAGS field is enabled in
any iSNSP message, then a new object entry SHALL NOT be created by
the message.
If the key attributes match an existing object in the iSNS directory
database, and the Update bit in the flags field is not enabled, then
the registration will replace the existing registration. The
existing object(s) specified in the RegDevAttr message shall be de-
registered. A new registration shall be created with the new
attribute value(s) in the registration request. Existing
associations between objects will be updated to reflect the new
information. For example, an existing Node object may be de-
registered and reregistered with a different Entity object as part
of a registration.
If the key attributes match an existing entry in the iSNS database
and the Update bit in the FLAGS field is enabled, then the new
attribute value(s) in the registration request SHALL update existing
values and may add new, additional attributes for the key entry.
Only non-key attributes can be updated. Existing associations
between objects will be maintained. If the update would cause a
change in associations, then the error ôInvalid Registration Updateô
SHALL be returned. For example, if a RegDevAttr message with an
Entity Identifier key for one entity contains a Node attribute
associated with another entity, then an error shall be returned.
7.6.5.2 Device Attribute Query Request (DevAttrQry)
The DevAttrQry message type is 0x0002. The DevAttrQry message
provides an iSNS client with the means to query the iSNS server for
network entity attributes.
The Source attribute of the DevAttrQry message is as defined in
Section 7.6.1. The source is used to scope the query to the
Discovery Domains that the source attribute is a member of.
The Key Attribute(s) follow the source attribute in the message
payload. The attributes returned by the query will be from objects
Gibbons, Tseng, Monia Standards Track 51
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WHERE the Key Attribute(s) match the object. The Key Attributes map
to a type of object.
The DevAttrQry message shall support the following minimum set of
Key Attributes:
Valid Key Attributes for Queries
--------------------------------
Entity Identifier
Entity Protocol
Portal IP-Address
Portal IP-Address, Portal TCP/UDP Port
iSCSI Node Type
iSCSI Identifier
iFCP Node Port WWN
iFCP Node Port Type
iFCP Node Port FC-4 Type
If the network entities matching key attributes are not in the same
Discovery Domain as the Source Attribute, then the results for the
network entity will not be included in the response message.
The Operating Attributes are the attributes whose values are being
queried.
7.6.5.3 Device Get Next Request (DevGetNext)
The DevGetNext message type is 0x0003. This message provides the
iSNS client with the means to sequentially retrieve Entity, Portal,
iSCSI Node, iFCP Node, or FC Node attributes from DD's to which the
client has access.
The Source attribute of the DevGetNext message is as defined in
Section 7.6.1. The source is used to scope the Get Next process to
the Discovery Domains that the source attribute is a member of.
The Key Attribute follows the source attribute in the message
payload. The Key Attribute may be an Entity Identifier, iSCSI Name,
Portal IP Address and TCP/UDP Port, FC Device WWNN, or iFCP Node
WWPN. If the key TLV length value entered is zero, signifying an
empty key value field, then the first accessible Entity Identifier,
iSCSI Name, Portal IP Address and TCP/UDP Port, FC Device, or iFCP
Node instance shall be returned to the client. DevGetNext SHALL
return the object that is stored sequentially after the object
matching the key provided. If the key provided matches the last
object instance, then the Error Code of "No Such Entry" SHALL be
returned in the response.
The values of the matching Operating Attributes listed in the
original DevGetNext message SHALL be returned in the DevGetNext
response.
7.6.5.4 Deregister Device Request (DeregDev)
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The DeregDev message type is 0x0004. An iSNS client port or device
is removed from the iSNS directory database by using DeregDev. Upon
receiving the DeregDev, the iSNS server removes all object
registrations associated with the Key Attribute in the payload.
The DeregDev request message payload contains a Source Attribute and
Key Attribute(s). The Source attribute of the DeregDev message is
as defined in Section 7.6.1. Valid Key Attributes are shown below:
Valid Key Attributes for DeregDev
---------------------------------
Entity Identifier
Portal IP-Address
Portal IP-Address, Portal TCP/UDP Port
iSCSI Name
iFCP Node Port WWN
iFCP Device Node WWN
The removal of the object will initiate an SCN message to registered
iSNS clients that are in the same DD as the removed device or port.
After removing the port or device, the iSNS server sends back an
acknowledgement to the iSNS client.
If all nodes associated with an entity are deregistered from that
entity, then the entity SHALL also be removed UNLESS the entity
(through one or more Portals) is responding to ESI's.
If all Portals associated with an entity are deregistered from that
entity, then that entity SHALL be removed from the iSNS database.
7.6.5.5 SCN Register Request (SCNReg)
The SCNReg message type is 0x0005. The State Change Notification
Registration Request (SCNReg) message allows an iSNS client to
register a STORAGE NODE to receive State Change Notification (SCN)
messages. SCN messages allow an iSNS client to be notified of
changes within the DD or network (if administratively allowed) that
the device is a member of.
The SCNReg request message payload contains a Source Attribute, a
Key Attribute(s), and an Operating Attribute. The Source attribute
of the SCNReg message is as defined in Section 7.6.1. Valid Key
Attributes for an SCNReg are shown below:
Valid Key Attributes for SCNReg
--------------------------------
iSCSI Name (iSCSI Only)
Port WWN (iFCP Only)
The iSCSI nodes or iFCP nodes matching the Key Attributes are
registered to receive SCNs.
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The Operating Attribute is the SCN Bitmap attribute for the protocol
type. The bitmap indicates those INTERESTED EVENT TYPES the node or
entity is registering for.
7.6.5.6 SCN Deregister Request (SCNDereg)
The SCNDereg message type is 0x0006. The SCNDereg message allows an
iSNS client to disable State Change Notification (SCN) messages.
The SCNDereg request message payload contains a Source Attribute and
Key Attribute(s). The Source attribute of the SCNDereg message is
as defined in Section 7.6.1. Valid Key Attributes for an SCNDereg
are shown below:
Valid Key Attributes for SCNDereg
---------------------------------
iSCSI Name (iSCSI only)
Port WWN (iFCP only)
The network entities matching the Key Attributes are deregistered
for SCNs.
There are no Delimiter or Operating Attributes in the SCNDereg
message.
7.6.5.7 SCN Event (SCNEvent)
The SCNEvent message type is 0x0007. The SCNEvent is a message
generated by an iSNS client. The SCNEvent allows the client to
request generation of a State Change Notification (SCN) message by
the iSNS server. The SCN, sent by the iSNS server, then notifies
other registered network nodes or entities within a DD or network
(if administratively allowed) of the change indicated in the
SCNEvent.
Most SCNs are automatically generated by the iSNS when network nodes
or entities are registered or deregistered from the directory
database. SCNs are also be generated when a network management
application makes changes to the DD membership in the iSNS.
However, a network entity can trigger a SCN by using SCNEvent.
The SCNEvent message payload contains a Source Attribute, Key
Attribute, and Operating Attribute. The Source attribute of the
SCNEvent message is as defined in Section 7.6.1. Valid Key
Attributes for an SCNEvent are shown below:
Valid Key Attributes for SCNEvent
---------------------------------
iSCSI Name (iSCSI Only)
Port WWN (iFCP Only)
The Operating Attributes section SHALL contain the SCN Event Bitmap
attribute. The bitmap indicates the event that caused the SCNEvent
to be generated.
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7.6.5.8 State Change Notification (SCN)
The SCN message type is 0x0008. The SCN is a message generated by
the iSNS server which allows a registered network node or entity to
be notified of changes within a DD, network (if administratively
allowed), or about device registration parameter updates in the iSNS
directory database.
The types of events that a network node or entity will be notified
about are based on the value of the SCN Event Bitmap for the node or
entity.
The format of the SCN payload is shown below:
+----------------------------------------+
| Destination Attribute |
+----------------------------------------+
| Timestamp |
+----------------------------------------+
| Source Attribute[1] |
+----------------------------------------+
| Source SCN Bitmap[1] |
+----------------------------------------+
| Source Attribute [2](if present) |
+----------------------------------------+
| Source SCN Bitmap [2](if present) |
+----------------------------------------+
| Source Attribute [3](if present) |
+----------------------------------------+
| Source SCN Bitmap [3](if present) |
+----------------------------------------+
| . . . |
+----------------------------------------+
All payload attributes are in TLV format.
The Destination Attribute is the node or entity identifier that is
receiving the SCN. The Destination Attribute can be an Entity
Identifier, iSCSI Name, or iFCP Port Name.
The Timestamp field, using the Timestamp TLV format, indicates the
time the SCN was generated.
The Source Attribute is the object that caused the SCN to be
generated. The Source Attribute can be an Entity Identifier, iSCSI
Name, or iFCP Port Name.
The Source SCN Bitmap indicates the event that caused the SCN to be
generated. The SCN Bitmap is a 32 bit field, with the following
definitions:
Gibbons, Tseng, Monia Standards Track 55
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Bit Field Flag Description
--------- ----------------
0 CHANGE IN DD MEMBERSHIP
1 CHANGE IN NETWORK
2 CHANGE IN CLIENT REGISTRATION PARAMETERS
3 CLIENT ADDED
4 CLIENT REMOVED
All Others Reserved
7.6.5.9 DD Register (DDReg)
The DDReg message type is 0x0009. This message is used to create a
new Discovery Domain (DD), update an existing DD Symbolic Name,
and/or add DD members.
DDs are uniquely defined using DD_IDs. DD registration attributes
are described in section 6.8.
The DDReg message payload contains the Source Attribute, and
optionally Key and Operating Attributes. The Source attribute of the
DDReg message is as defined in Section 7.7.1.
A DDReg message with no key attribute results in creation of a new
Discovery Domain (DD) (in addition, the update flag MUST NOT be
set). If the DD_ID attribute (with non-zero length) is included
among the operating attributes in the DDReg message, then the new
Discovery Domain SHALL be assigned the value contained in that DD_ID
attribute. Otherwise, if the DD_ID attribute is not contained among
the operating attributes of the DDReg message, or if the DD_ID is an
operating attribute with TLV length of 0, then the iSNS SHALL assign
the DD_ID value that is returned in the DDReg Response message.
The Operating Attributes can contain the iSCSI Node Identifier or
iFCP WWPN of iSNS clients to be added to the DD. It may also
contain the DD_Symbolic_Name of the DD.
This message shall add any DD members listed as operating attributes
to the Discovery Domain specified by the DD_ID. In addition, if the
DD_Symbolic_Name is an operating attribute, then it will be stored
in the iSNS as the DD_Symbolic_Name for the specified Discovery
Domain.
7.6.5.10 DD Deregister (DDDereg)
The DDDereg message type is 0x000A. This message allows an iSNS
client to deregister an existing Discovery Domain (DD) or remove
members from an existing DD.
DDs are uniquely defined using DD_IDs. DD registration attributes
are described in section 6.8.
The DDDereg message payload contains a Source Attribute, Key
Attribute, and Operating Attributes. The Source attribute of the
DDDereg message is as defined in Section 7.6.1.
Gibbons, Tseng, Monia Standards Track 56
iSNS June 2001
The Key Attribute for a DDDereg message is the DD ID for the domain
being removed, or having members removed. If the DD ID matches an
existing DD, and there are no operating attributes, then the DD will
be removed and a success error code returned. If the key attribute
does not match an existing DD then the error code ôNo Such Entryö
will be returned.
If the DD ID matches an existing DD, and there are operating
attributes matching DD members, then the DD members identified by
the operating attributes SHALL be removed from the DD and a success
error code returned. If any of the operating attributes do not
match existing DD members, then the error code ôNo Such Entryö will
be returned, and no DD members shall be removed.
7.6.5.11 DDS Register (DDSReg)
The DDSReg message type is 0x000B. This message allows an iSNS
client to create a new Discovery Domain Set (DDS), update an
existing DDS Symbolic Name, or add DDS members.
DDSÆs are uniquely defined using DDS_IDÆs. DDS registration
attributes are described in section 6.8.
The DDSReg message payload contains the Source Attribute, and
optionally Key and Operating Attributes. The Source attribute of the
DDSReg message is as defined in Section 7.6.1.
A DDSReg message with no key attribute results in creation of a new
Discovery Domain Set (DDS) (in addition, the update flag MUST NOT be
set). If the DDS_ID attribute (with non-zero length) is included
among the operating attributes in the DDSReg message, then the new
Discovery Domain Set SHALL be assigned the value contained in that
DDS_ID attribute. Otherwise, if the DDS_ID attribute is not
contained among the operating attributes of the DDSReg message, or
if the DDS_ID is an operating attribute with TLV length of 0, then
the iSNS SHALL assign the DDS_ID value that is returned in the
DDSReg Response message.
The Operating Attributes can contain the DDS_Symbolic_Name and the
DD_IDÆs of Discovery Domains to be added to the DDS.
This message shall add any DDS members listed as operating
attributes to the Discovery Domain Set specified by the DDS_ID key
attribute. In addition, if the DDS_Symbolic_Name is an operating
attribute, then it will be stored in the iSNS as the
DDS_Symbolic_Name for the specified Discovery Domain Set.
7.6.5.12 DDS Deregister (DDSDereg)
The DDSDereg message type is 0x000C. This message allows an iSNS
client to deregister an existing Discovery Domain Set (DDS) or
remove some DDÆs from an existing DDS.
Gibbons, Tseng, Monia Standards Track 57
iSNS June 2001
DDSs are uniquely defined using DDS_IDs. DDS registration
attributes are described in section 6.8.
The DDSDereg message payload contains a Source Attribute, Key
Attribute, and Operating Attributes. The Source attribute of the
DDSDereg message is as defined in Section 7.6.1.
The Key Attribute for a DDSDereg message is the DDS ID for the set
being removed, or having members removed. If the DDS ID matches an
existing DDS, and there are no operating attributes, then the DDS
will be removed and a success error code returned. If the key
attribute does not match an existing DDS then the error code ôNo
Such Entryö will be returned.
If the DDS ID matches an existing DDS, and there are operating
attributes matching DDS members, then the DDS members will be
removed from the DDS and a success error code returned. If any of
the operating attributes do not match existing DDS members, then the
error code ôNo Such Entryö will be returned and no DDS members shall
be removed.
7.6.5.13 Entity Status Inquiry (ESI)
The ESI message type is 0x000D. This message is sent by the iSNS
server, and is used to verify that an iSNS client portal is
reachable and available. The ESI message is sent to the ESI UDP port
provided during registration, or the TCP connection used for ESI
registration, depending on which communication type that is being
used.
The ESI message payload contains several attributes in TLV format,
including the current iSNS timestamp, the EID, the Portal IP
Address, and Portal TCP/UDP Port.
The ESI response message payload contains the Attributes from the
original ESI message.
If the iSNS client portal fails to respond to three consecutive ESI
messages, then the iSNS SHALL remove that client portal from the
iSNS database. If there are no other remaining ESI monitored portals
for the associated entity, then the entity SHALL also be removed.
The appropriate State Change Notifications, if any, SHALL be
triggered.
7.6.5.14 Name Service Heartbeat (Heartbeat)
This optional message can be regularly issued by the iSNS server to
a broadcast or multicast address at an administratively-configured
time interval. The payload of this message is shown below:
Gibbons, Tseng, Monia Standards Track 58
iSNS June 2001
MSb LSb
31 0
+----------------------------------------+
| |
| IP-Address |
| |
| |
+----------------------------------------+
| iSNS TCP Port | iSNS UDP Port |
+----------------------------------------+
| Interval |
+----------------------------------------+
| Counter |
+----------------------------------------+
The heartbeat payload contains:
IP-Address : the IP_Address of the server in IPv6 format
TCP Port : the TCP Port of the server currently in use
UDP Port : the UDP Port of the server currently in use, otherwise 0
Interval : the interval, in seconds, of the heartbeat
Counter : a monotonically incrementing count of heartbeats sent
This information is NOT in TLV format.
The content of the remainder of this message is vendor-specific.
Vendors may use additional fields to coordinate between multiple
iSNS servers to identify vendor specific features.
This message allows iSNS clients listening to the broadcast or
multicast address to discover the IP address of the iSNS server. It
may also be used by backup iSNS servers to monitor the health and
status of the primary iSNS server.
There is no response message to the Name Service Heartbeat.
7.6.5.15 Request Switch ID (RqstSwId)
The RqstSwId message type is 0x0011. This optional message is used
for iFCP Transparent Mode to allocate non-overlapping SWITCH_ID
values between 1 and 239. The iSNS server becomes the address
assignment authority for the entire iFCP fabric. To obtain multiple
SWITCH_ID values, this request must be repeated multiple times to
the iSNS server.
The RqstSwId payload contains three TLV attributes in the following
order: the requesting entity EID as the source attribute, the Space
Identifier as the key attribute, and Preferred ID as the operating
attribute. The Space Identifier is a string identifying the domain
space for which the iSNS server shall allocate non-overlapping
integer SWITCH_ID values between 1 and 239. The Preferred_ID is the
nominal SWITCH_ID value requested by the iSNS client. If the
Preferred_ID value is available and has not been already allocated
for the Space_Identifier specified in the message, the iSNS server
Gibbons, Tseng, Monia Standards Track 59
iSNS June 2001
shall return the requested Preferred_ID value as the Assigned_ID to
the requesting client.
The RqstSwId response contains an Error Code, and the TLV attribute
Assigned ID, which contains the integer value in the space
requested. If no further unallocated values are available from this
space, the iSNS server SHALL respond with the error code 18
"SWITCH_ID not available".
Once a SWITCH_ID value has been allocated to an iSNS client by the
iSNS server for a given Space_Identifier, that SWITCH_ID value shall
not be reused until it has been deallocated, or the ESI message
detects that the iSNS client no longer exists on the network.
The iSNS server and client SHALL use TCP to transmit and receive
RqstSwId, RqstSwIdRsp, RlseSwId, and RlseSwIdRsp messages.
7.6.5.16 Release Switch ID (RlseSwId)
The RlseSwId message type is 0x0012. This optional message may be
used by iFCP Transparent Mode to release integer identifier values
used to assign 3-byte Fibre Channel PORT_ID values.
The RlseSwId message contains three TLV attributes in the following
order: the requesting entity EID as the source attribute, the
Space_Identifier as the key attribute, and Assigned_ID as the
operating attribute. Upon receiving the RlseSwId message, the iSNS
server shall deallocate the SWITCH_ID value contained in the
Assigned_ID attribute for the Space_Identifier attribute specified.
Upon deallocation, that SWITCH_ID value can now be requested by, and
assigned to, a different iSNS client.
The iSNS server and client SHALL use TCP to transmit and receive
RqstSwId, RqstSwIdRsp, RlseSwId, and RlseSwIdRsp messages.
7.6.5.17 Get Switch IDs (GetSwIds)
The GetSwIds message type is 0x0013. This optional message is used
to learn the currently-allocated SWITCH_ID values for a given
Space_Identifier.
The GetSwIds message payload contains a Source Attribute and Key
Attribute. The Source attribute of the GetSwIds message is as
defined in Section 7.6.1.
The Key Attribute for the GetSwIds message is the Space_Identifier.
The response to this message returns all of the SWITCH_ID values
that have been allocated for the Space_Identifier specified.
7.7 Response Messages
The iSNSP response message payloads contain an Error Code, followed
by a list of attributes, and have the following format:
Gibbons, Tseng, Monia Standards Track 60
iSNS June 2001
MSb LSb
31 0
+----------------------------------------+
| 4-byte ERROR CODE |
+----------------------------------------+
| Key Attribute[1] (if present) |
+----------------------------------------+
| Key Attribute[2] (if present) |
+----------------------------------------+
| Key Attribute[3] (if present) |
+----------------------------------------+
| . . . |
+----------------------------------------+
| - Delimiter Attribute - (if present) |
+----------------------------------------+
| Operating Attribute[1] (if present) |
+----------------------------------------+
| Operating Attribute[2] (if present) |
+----------------------------------------+
| Operating Attribute[3] (if present) |
+----------------------------------------+
| . . . |
+----------------------------------------+
The iSNS Response messages will be sent to the iSNS Client IP
Address and the originating TCP/UDP Port that was used for the
associated registration and query message.
7.7.1 Error Code
The first field in an iSNSP response message payload is the Error
Code for the operation that was performed. The Error Code format is
defined in section 7.4.
7.7.2 Key Attributes in Response
Depending on the specific iSNSP request, the response message will
contain Key Attributes. For example, a Register Device Attribute
Response message will contain the Key Attributes used in the Device
Attribute Registration with the assigned values, if they were
assigned by the iSNS.
7.7.3 Delimiter Attribute in Response
The Delimiter Attribute separates the key and operating attributes
in a response message, if they exist. The Delimiter Attribute has a
tag value of 0 and a length value of 0. The Delimiter Attribute is
effectively 8 Bytes long, a 4 Byte tag containing 0x00000000, and a
4 Byte length field containing 0x00000000.
7.7.4 Operating Attributes in Response
The Operating Attributes in a response are the results related to
the iSNS registration or query operation being performed.
Gibbons, Tseng, Monia Standards Track 61
iSNS June 2001
The number of Operating Attributes in the response depends on the
specific iSNSP request or query response. For example, the
Operating Attributes in a Device Attribute Query Response message
are the set of Operating Attributes from network entity entries that
matched the Key Attributes in the associated Device Attribute Query
message.
7.7.5 Registration and Query Message Types
The following describes each query and message type.
7.7.5.1 Register Device Attribute Response (RegDevRsp)
The RegDevRsp message type is 0x8001. The RegDevRsp message
contains the results for the RegDevAttr message with the same
TRANSACTION ID.
The Error Code contains the operation results. If the registration
completed successfully the code of ôNo Errorö is returned. If an
error occurred then the appropriate code will be returned.
The Key Attributes contain the set of keys for the objects
registered by the Register Device Attribute message. If the iSNS
assigned a unique Entity Identifier for a network entity, then the
key attribute field shall contain the assigned Entity Identifier.
There are no Operating Attributes in the RegDevRsp message.
7.7.5.2 Device Attribute Query Response (DevAttrQryRsp)
The DevAttrQryRsp message type is 0x8002. The DevAttrQryRsp message
contains the results for the DevAttrQry message with the same
TRANSACTION ID.
The Error Code contains the operation results. If the query
completed successfully the code of ôNo Errorö is returned. If an
error occurred then the appropriate code will be returned.
For a successful query result, the DevAttrQryRsp Operating
Attributes will contain the results of the original DevAttrQry
message.
7.7.5.3 Device Get Next Response (DevGetNextRsp)
The DevGetNextRsp message type is 0x8003. The DevGetNextRsp message
contains the results for the DevGetNext message with the same
TRANSACTION ID.
The Error Code contains the operation results. If the operation
completed successfully the code of ôNo Errorö is returned. If an
error occurred then the appropriate code will be returned.
Gibbons, Tseng, Monia Standards Track 62
iSNS June 2001
The Key Attribute field contains the next key, in sequential order,
after the Key Attribute used in the DevGetNext message.
The Operating Attribute field contains the same attributes as in the
DevGetNext message. The values of the Operating Attributes are the
attribute values associated with the key returned.
7.7.5.4 Deregister Device Response (DeregDevRsp)
The DeregDevRsp message type is 0x8004. If the DeregDev operation
completed successfully then the code of ôNo Errorö is returned. If
an error occurred then the appropriate code will be returned.
The DeregDevRsp message does not contain any key or operating
attributes.
7.7.5.5 SCN Register Response (SCNRegRsp)
The SCNRegRsp message type is 0x8005. If the SCNReg operation
completed successfully then the code of ôNo Errorö is returned. If
an error occurred then the appropriate code will be returned.
The SCNRegRsp message does not contain any key or operating
attributes.
7.7.5.6 SCN Deregister Response (SCNDeregRsp)
The SCNDeregRsp message type is 0x8006. If the SCNDereg operation
completed successfully then the code of ôNo Errorö is returned. If
an error occurred then the appropriate code will be returned.
The SCNDeregRsp message does not contain any key or operating
attributes.
7.7.5.7 SCN Event Response (SCNEventRsp)
The SCNEventRsp message type is 0x8007. If the SCNEvent operation
completed successfully then the Error Code of ôNo Errorö is
returned. If an error occurred then the appropriate code will be
returned.
The SCNEventRsp message does not contain any key or operating
attributes.
7.7.5.8 SCN Response (SCNRsp)
The SCNRsp message type is 0x8008. This message is sent by an iSNS
client, and provides confirmation that the SCN message was received
and processed.
If the SCN operation completed successfully, then the Error Code of
ôNo Errorö is returned by the iSNS client. If an error occurred
then the appropriate code will be returned.
Gibbons, Tseng, Monia Standards Track 63
iSNS June 2001
The SCNRsp response message payload also contains the SCN
Destination Attribute representing the node or entity identifier
that received the SCN.
7.7.5.9 DD Register Response (DDRegRsp)
The DDRegRsp message type is 0x8009. If the DDReg operation
completed successfully then the code of ôNo Errorö is returned. If
an error occurred then the appropriate code will be returned.
If successful, the DD ID of the DD created or updated during the
DDReg operation will be returned as an operating attribute of the
message.
7.7.5.10 DD Deregister Response (DDDeregRsp)
The DDDeregRsp message type is 0x800A. If the DDDereg operation
completed successfully then the code of ôNo Errorö is returned. If
an error occurred then the appropriate code will be returned.
The DDDeregRsp message does not contain any key or operating
attributes.
7.7.5.11 DDS Register Response (DDSRegRsp)
The DDSRegRsp message type is 0x800B. If the DDSRegRsp operation
completed successfully then the code of ôNo Errorö is returned. If
an error occurred then the appropriate code will be returned.
If successful, the DDS ID of the DDS created or updated during the
DDSReg operation will be returned as an operating attribute of the
message.
7.7.5.12 DDS Deregister Response (DDSDeregRsp)
The DDSDeregRsp message type is 0x800C. If the DDSDeregRsp operation
completed successfully then the code of ôNo Errorö is returned. If
an error occurred then the appropriate code will be returned.
The DDSDeregRsp message does not contain any key or operating
attributes.
7.7.5.13 Entity Status Inquiry Response (ESIRsp)
The ESIRsp message type is 0x800D. This message is sent by an iSNS
client, and provides confirmation that the ESI message was received
and processed.
The ESIRsp response message payload contains the attributes from the
original ESI message. These attributes represent the iSNS client
portal that is responding to the ESI. The ESIRsp Attributes are in
the order they were provided in the original ESI message. An error
code of "No Error" is returned.
Gibbons, Tseng, Monia Standards Track 64
iSNS June 2001
Upon receiving the ESIRsp from the iSNS client, the iSNS server
SHALL update the timestamp attribute for that client entity and
portal.
7.7.5.14 Request Switch ID Response (RqstSwIdRsp)
The RqstSwIdRsp message type is 0x8011. This message provides the
response for RqstSwId.
The RqstSwId response contains an Error Code and the TLV attribute
Assigned ID, which contains the integer value in the space
requested. If no further unallocated values are available from this
space, the iSNS server SHALL respond with the error code 19
"SWITCH_ID not available".
Once a SWITCH_ID value is allocated by the iSNS server, it shall not
be reused until it has been deallocated by the iSNS client to which
the value was assigned, or the ESI message detects that the iSNS
client no longer exists on the network.
The iSNS server and client SHALL use TCP to transmit and receive
RqstSwId, RqstSwIdRsp, RlseSwId, and RlseSwIdRsp messages.
7.7.5.15 Release Switch ID Response (RlseSwIdRsp)
The RlseSwIdRsp message type is 0x8012. This message provides the
response for RlseSwId. The response contains an Error indicating if
the request was successful or not. If the Assigned_ID value in the
original RlseSwId message is not allocated, then the iSNS server
SHALL respond with this message using the error code 20 ôSWITCH_ID
not allocatedö.
The iSNS server and client SHALL use TCP to transmit and receive
RqstSwId, RqstSwIdRsp, RlseSwId, and RlseSwIdRsp messages.
7.7.5.16 Get Switch IDs Response (GetSwIdRsp)
The GetSwIdsResp message type is 0x8013. This optional message is
used determine which SWITCH_ID values have been allocated for the
Space_Identifier specified in the original GetSwId request message.
The GetSwIds response message payload contains an error code
indicating if the request was successful, and a list of the Assigned
IDs from the space requested. The Assigned_ID attributes are listed
in TLV format.
7.8 Vendor Specific Messages
Vendor-specific iSNSP messages have a functional ID of between
0x0100 and 0x01FF, while vendor-specific responses have a functional
ID of between 0x8100 and 0x81FF. The first key attribute in a
vendor-specific message SHALL be the company OUI (tag=256)
identifying original creator of the proprietary iSNSP message. The
contents of the remainder of the message is vendor-specific.
Gibbons, Tseng, Monia Standards Track 65
iSNS June 2001
8. Security Considerations
8.1 Data Integrity and Authentication
Data integrity and authentication requirements for communication
between iSNS clients and server can be achieved through use of the
authentication block described in section 7.5. This data integrity
and authentication mechanism is compatible with that used by Service
Location Protocol [RFC2608].
8.2 Confidentiality
If the operational evironment requires confidentiality in iSNSP
queries and responses, then the iSNSP shall be used with Transport
Layer Security (TLS). None of the information stored in the iSNS
database is inherently confidential. This includes X.509
certificates, which should contain only public keys. In these cases
where confidentiality is not required, the iSNS can be used only
with the message authentication block described in section 7.5.
8.3 Security Model
The iSNS server will leverage existing security mechanisms currently
used to secure resources such as DNS servers, e-mail relays servers,
and other sensitive and otherwise vulnerable network resources.
Existing firewalls technology can protect against active attacks
from the Public Internet.
9. References
[RFC1035] Domain Implementation and Specification
[RFC1305] Network Time Protocol (Version 3)
[STD0035] Domain Name System
[RFC2065] Domain Name System Security Extensions
[RFC2608] Service Location Protocol, Version 2
[FC-GS-2] Fibre Channel Generic Services-2, ANSI NCITS 288
[FC-GS-3] Fibre Channel Generic Services-3, NCITS Working
Draft Rev 7.01, November 28, 2000
[RFC2609] Service Templates and Service
[IEEE802.1Q] Standard for Virtual Bridged Local Area Networks
[RFC1510] The Kerberos Network Authentication Service
[DSS] FIPS PUB 186-2, National Institute of Standards and
Technology, Digital Signature Standard(DSS),
Technical Report
[802-1990] ANSI/IEEE Std 802-1990, Name: IEEE Standards for
Local and Metropolitan Area Networks: Overview and
Architecture
[SPC] SCSI-3 Primary Commands, ANSI NCITS 995D, Revision
11a
[iSCSI-SLP] Finding iSCSI Targets and Name Servers Using SLP,
draft-bakke-iscsi-slp-00.txt
[iSCSI-NDR] iSCSI Naming and Discovery Requirements,
draft-ietf-ips-iscsi-name-disc-00.txt
Gibbons, Tseng, Monia Standards Track 66
iSNS June 2001
1 Bradner, S., "The Internet Standards Process -- Revision 3", BCP
9, RFC 2026, October 1996.
2 Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997
10. Author's Addresses
Josh Tseng
Kevin Gibbons
Charles Monia
Nishan Systems
3850 North First Street
San Jose, CA 95134-1702
Phone: (408) 519-3749
Email: jtseng@nishansystems.com
Franco Travostino
Nortel Networks
3 Federal Street
Billerica, MA 01821
Phone: 978-288-7708
Email: travos@nortelnetworks.com
Kenneth Hirata
Vixel Corporation
Irvine, CA 92618
Phone: (949) 450-6100
Email: khirata@vixel.com
Mark Bakke
Cisco Systems
6450 Wedgewood Road
Maple Grove, MN 55311
Phone: 763-398-1054
Email: mbakke@cisco.com
John Dowdy
IBM
4205 South Miami Blvd
Research Triangle Park, NC 27709
Email: jdowdy@us.ibm.com
Phone: (919)254-5632
Howard Hall
Pirus Networks
43 Nagog Park
Acton, MA 01720
Email: howard@pirus.com
Phone: 978-206-9103
Gibbons, Tseng, Monia Standards Track 67
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Full Copyright Statement
"Copyright (C) The Internet Society (date). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph
are included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE."
Gibbons, Tseng, Monia Standards Track 68
iSNS June 2001
Appendix A - iSNS Examples
A.1 iSCSI Initialization Example
This example assumes an SLP Service Agent (SA) has been implemented
on the iSNS host, and an SLP User Agent (UA) has been implemented on
the iSNS initiator. See [RFC2608] for further details on SA's and
UA's. This example also assumes the target is configured to use the
iSNS, and have its access control policy subordinated to the iSNS.
Gibbons, Tseng, Monia Standards Track 69
iSNS June 2001
A.1.1 Simple iSCSI Target Registration
In this example, a simple target with a single iSCSI name registers
with the iSNS. The target has not been assigned a Fully Qualified
Domain Name (FQDN) by the administrator.
+--------------------------+------------------+-------------------+
| iSCSI Target Device | iSNS |Management Station |
+--------------------------+------------------+-------------------+
|Discover iSNS--SLP------->| |/*mgmt station is |
| |<--SLP--iSNS Here:| administratively |
| | 192.36.53.1 | authorized to view|
| | | all DD's. Device |
| | | NAMEabcd has been |
| RegDevAttr--------->| | previously placed |
|Oper Attrs: | | into DDabcd******/|
|tag=1: NULL | | |
|tag=2: "iSCSI" | | |
|tag=16: "192.36.4.5" | | |
|tag=17: "5001" | | |
|tag=19: 0 | | |
|tag=32: "NAMEabcd" | | |
|tag=33: "target" | | |
|tag=34: "disk 1" | | |
| |<---RegDevAttrRsp | |
| |SUCCESS | |
| |tag=1: "iSNS:0001"| |
| |tag=16: "192.36.4.5" |
| |tag=17: "5001" | |
| |tag=32: "NAMEabcd"| |
| | | |
| DevAttrQry--------->| SCN-------->| |
|Src:(tag=32) "NAMEabcd" |(or SNMP trap) | |
|Key:(tag=2) "iSCSI" |tag=1: "iSNS:0001" |
|Key:(tag=33) "initiator" |dest: "mgmt.foo.com" |
|Oper Attrs: |CHANGE IN NETWORK | |
|tag=16: NULL | | |
|tag=17: NULL | |<-------SCNRsp |
|tag=32: NULL | | |
|/*Query asks for all iSCSI| | |
|devices' IP address, port |<---DevAttrQryRsp | |
|number, and Name*/ |SUCCESS | |
| |tag=16:"192.36.4.1" |
| |tag=17:"50000" | |
| |tag=32:"devpdq" | |
| |tag=16:"192.1.3.2"|<-----DevAttrQry |
| |tag=17:"50000" |src: ôMGMTname1ö |
| |tag=32:"devrst" |key:(tag=1)iSNS:0001
| | |Op Attrs: |
|/*************************| |tag=16: NULL |
|Our target "iSNS:0001" | |tag=17: NULL |
|discovers two initiators | |tag=32: NULL |
|in the same DD. It will | | |
Gibbons, Tseng, Monia Standards Track 70
iSNS June 2001
|accept iSCSI logins from | | |
|these two identified | | |
|initiators presented by | | |
|iSNS*********************/| DevAttrQryRsp--->| |
| |SUCCESS | |
| |tag=16: 192.36.4.5| |
| |tag=17: 5001 | |
| |tag=32: NAMEabcd | |
+--------------------------+------------------+-------------------+
A.1.2 Target Registration and DD Configuration
In this example, a more complex target registers with the iSNS.
This target has been configured with a Fully Qualified Domain Name
(FQDN) in the DNS servers, and the user wishes to use this
identifier for the device. Also, the user wishes to use public key
certificates in the iSCSI login authentication.
+--------------------------+------------------+-------------------+
| iSCSI Target Device | iSNS |Management Station |
+--------------------------+------------------+-------------------+
|Discover iSNS--SLP--> | |/*mgmt station is |
| |<--SLP--iSNS Here:| administratively |
| | 192.36.53.1 | authorized to view|
| RegDevAttr--> | | all DD's ********/|
|Oper Attrs: | | |
|tag=1: "jbod1.foo.com" | | |
|tag=2: "iSCSI" | | |
|tag=16: "192.36.34.4" | | |
|tag=17: "5001" | | |
|tag=19: "5 seconds" | | |
|tag=16: "192.36.53.5" | | |
|tag=17: "5001" | | |
|tag=32: "NAMEabcd" | | |
|tag=33: "Target" |/*****************| |
|tag=34: "Volume 1" |jbod1.foo.com is | |
|tag=40: X.509 cert blob 1 |now registered in | |
|tag=32: "NAMEefgh" |iSNS, but is not | |
|tag=33: "Target" |in any DD. Therefore, |
|tag=34: "Volume 2" |no other devices | |
|tag=40: X.509 cert blob 2 |can "see" it. | |
| |*****************/| |
| |<--RegDevAttrRsp | |
| |SUCCESS | |
| |tag=1: "jbod1.foo.com" |
| |tag=16: "192.36.34.4" |
| |tag=17: "5001" | |
| |tag=16: "192.36.53.5" |
| |tag=17: "5001" | |
| |tag=32: "NAMEabcd"| |
| |tag=32: "NAMEefgh"| |
| | | |
| | SCN------> | |
| | (or SNMP trap) | |
Gibbons, Tseng, Monia Standards Track 71
iSNS June 2001
| |tag=1: jbod1.foo.com |
| |dest: mgmt.foo.com| |
| |CHANGE IN NETWORK | |
| | | |
| | |<--SCNRsp |
| | |<--DevAttrQry |
| | |src: mgmt.foo.com |
| | |key: (tag=1) |
| | | jbod1.foo.com |
| | |Op Attr: (tag=2) |
| | |Op Attr: (tag=16) |
| | |Op Attr: (tag=17) |
| | |Op Attr: (tag=32) |
| | | |
| | DevAttrQryRsp--> | |
| |SUCCESS | |
| |tag=2: "iSCSI" | |
| |tag=16: 192.36.34.4 |
| |tag=17: 5001 | |
| |tag=16: 192.36.53.5 |
| |tag=17: 5001 |/**Mgmt Station ***|
| |tag=32:"NAMEabcd" |displays device, |
| |tag=32:"NAMEefgh" |the operator decides
| | |to place "NAMEabcd"|
| | |into Domain "DDxyz"|
|/*************************| |******************/|
|Target is now registered | | |
|in iSNS. It has been placed |<--DDReg |
|in DDxyz by management | |src: "mgmt.foo.com"|
|station. | |key: "DDxyz ID" |
|*************************/| |Op Attr: |
| | |tag=32: "NAMEabcd" |
| | DDRegRsp----->| |
| | SUCCESS | |
+--------------------------+------------------+-------------------+
A.1.3 Initiator Registration and Target Discovery
The following example illustrates a new initiator registering with
the iSNS, and discovering the target NAMEabcd from the example in
A.1.2.
+--------------------------+------------------+-------------------+
| iSCSI Initiator | iSNS |Management Station |
+--------------------------+------------------+-------------------+
|Discover iSNS--SLP--> | |/*mgmt station is |
| |<--SLP--iSNS Here:| administratively |
| | 192.36.53.1 | authorized to view|
|RegDevAttr--> | | all DD's ********/|
|Oper Attrs: | | |
|tag=1: "svr1.foo.com" | | |
|tag=2: "iSCSI" | | |
|tag=16: "192.20.3.1" |/*****************| |
|tag=17: "5001" |Device not in any | |
Gibbons, Tseng, Monia Standards Track 72
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|tag=19: 5 seconds |DD, so it is | |
|tag=32: "NAMEijkl" |inaccessible by | |
|tag=33: "Initiator" |other devices | |
|tag=34: "Server1" |*****************/| |
|tag=39: X.509 cert blob 3 | | |
| |<--RegDevAttrRsp | |
| |SUCCESS | |
| |tag=1: "svr1.foo.com" |
| |tag=16: "192.20.3.1" |
| |tag=17: "5001" | |
| |tag=32: "NAMEijkl"| |
| | | |
| | SCN------> | |
| | (or SNMP trap) | |
| |tag=1: svr1.foo.com |
| |dest: mgmt.foo.com| |
| |CHANGE IN NETWORK | |
| | | |
| | |<------SCNRsp |
| | |<----DevAttrQry |
| | |src: mgmt.foo.com |
| | |key: (tag=1) |
| | | svr1.foo.com |
| | |Op Attr: (tag=2) |
| | |Op Attr: (tag=16) |
| | |Op Attr: (tag=17) |
| | |Op Attr: (tag=32) |
| | DevAttrQryRsp--> | |
| |SUCCESS | |
| |tag=2: "iSCSI" | |
| |tag=16:192.20.3.1 | |
| |tag=17: "5001" | |
| |tag=32:"NAMEijkl" | |
| | |/**Mgmt Station ***|
| | |displays device, |
| | |the operator decides
| | |to place "NAMEijkl"|
| | |into Domain "DDxyz"|
| | |with device NAMEabcd
| | |******************/|
| | |<--DDReg |
| | |src: (tag=1) |
| | | "mgmt.foo.com" |
| | |key: "DDxyz ID" |
| | |tag=32: "NAMEijkl |
| | | |
| | DDRegRsp---->|/******************|
| | SUCCESS |"NAMEijkl" has been|
| | |moved to "DDxyz" |
| | |******************/|
| |<-----SCN | |
| |tag=32: "NAMEijkl"| |
| |CHANGE IN DD MEMBERSHIP |
| DevAttrQry----------->| | |
Gibbons, Tseng, Monia Standards Track 73
iSNS June 2001
|src: "NAMEabcd" |/*****************| |
|key:(tag=2) "iSCSI" |Note that NAMEabcd| |
|key:(tag=33) "Target" |also receives an | |
|Op Attr: (tag=16) |SCN that NAMEijkl | |
|Op Attr: (tag=17) |is in the same DD | |
|Op Attr: (tag=32) |*****************/| |
|Op Attr: (tag=34) | | |
|Op Attr: (tag=40) |<-----AttrQryRsp | |
| |SUCCESS | |
| |tag=16: 192.36.34.4 |
| |tag=17: 5001 | |
| |tag=16: 192.36.53.5 |
| |tag=17: 5001 | |
| |tag=32: NAMEabcd | |
| |tag=34: Volume 1 | |
| |tag=40: X.509 cert blob 2 |
| | | |
|/***The initiator has discovered | |
|the target, and has everything | |
|needed to complete iSCSI login | |
|The same process occurs on the | |
|target side; the SCN prompts the | |
|target to download the list of | |
|authorized initiators from the | |
|iSNS (i.e., those initiators in the | |
|same DD as the target.************/ | |
+--------------------------+------------------+-------------------+
Gibbons, Tseng, Monia Standards Track 74
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