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Versions: (draft-tseng-ips-isns) 00 01 02 03
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-02.txt> Josh Tseng
Expires October 2001 Charles Monia
Nishan Systems
Franco Travostino
Nortel Networks
Ken Hirata
Vixel Corporation
Mark Bakke
Cisco Systems
Jim Hafner
IBM Research
Howard Hall
Pirus Networks
April 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), Yaron
Gibbons, Tseng, Monia Standards Track
iSNS April 2001
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................................6
3.1.1 iSNS Protocol (iSNSP)........................................6
3.1.2 iSNS Client..................................................6
3.1.3 iSNS Server..................................................7
3.1.4 iSNS Database................................................7
3.2 iSNS Functional Components...................................7
3.2.1 Name Registration Service....................................7
3.2.2 Discovery Domain and Login Control Service...................7
3.2.3 State Change Notification Service............................8
3.3 iSNS and Domain Name System (DNS)............................9
3.4 iSNS and LDAP................................................9
3.5 iSNS Server Discovery.......................................10
3.6 iSNS and NAT................................................10
3.7 Interactions Between iSNS Infrastructures...................11
3.8 Deployment Architecture Diagram.............................13
4. iSNS Object Model...........................................13
4.1 NETWORK ENTITY Object.......................................14
4.2 PORTAL Object...............................................14
4.3 STORAGE NODE Object (iFCP and iSCSI Only)...................14
4.4 FC DEVICE Object (iFCP Only)................................14
4.5 DISCOVERY DOMAIN Object.....................................14
4.6 DISCOVERY DOMAIN SET Object.................................14
4.7 iSNS Database Model.........................................14
5. iSNS Implementation Requirements............................15
5.1 iSCSI Requirements..........................................15
5.1.1 Required Attributes for Support of iSCSI....................15
5.1.2 Attribute Descriptions for iSCSI Storage Systems............16
5.1.3 Example iSCSI Object Model Diagrams.........................17
5.1.4 Required Commands and Response Messages for Support of iSCSI19
5.2 iFCP Requirements...........................................20
5.2.1 Required Attributes for Support of iFCP.....................20
5.2.2 Attribute Descriptions for iFCP Gateways and FC devices.....21
Gibbons, Tseng, Monia Standards Track 2
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5.2.3 iFCP Attribute Requirements.................................22
5.2.3.1 Port_ID.....................................................23
5.2.4 Example iFCP Object Model Diagram...........................23
5.2.5 Required Commands and Response Messages for Support of iFCP.24
5.3 FCIP Requirements...........................................25
5.3.1 Required Attributes for Support of FCIP.....................25
5.3.2 Attribute Descriptions for FCIP Gateways....................25
5.3.3 Example FCIP Object Model Diagram...........................26
5.3.4 Required Commands and Response Messages for Support of FCIP.27
5.4 Attribute Descriptions for Discovery Domain Registration....28
6. iSNS Message Attributes.....................................28
6.1 iSNS Attribute Summary......................................29
6.2 Entity Identifier-Keyed Attributes..........................31
6.2.1. Entity Identifier (EID).....................................32
6.2.2 Entity Type.................................................32
6.2.3 Management IP Address.......................................32
6.2.4 Entity Registration Timestamp...............................32
6.2.5 Entity Certificate..........................................32
6.3 Portal-Keyed Attributes.....................................33
6.3.1 Portal IP-Address...........................................33
6.3.2 Portal TCP/UDP Port.........................................33
6.3.3 Portal Symbolic Name........................................33
6.3.4 Entity Status Inquiry Interval..............................33
6.3.5 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............................................34
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)..................................35
6.5.2 Port ID.....................................................35
6.5.3 Port Type...................................................35
6.5.4 iFCP Node Port Symbolic Name................................36
6.5.5 iFCP Node Fabric Port Name (FWWN)...........................36
6.5.6 FC Hard Address.............................................36
6.5.7 FC Port IP Address..........................................36
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............................................37
6.5.12 iFCP Node SCN Bitmap........................................37
6.5.13 iFCP Node Certificate.......................................38
6.6 iFCP FC Device Node-Keyed Attributes........................38
6.6.1 iFCP FC Device Node Name (WWNN).............................38
6.6.2 iFCP FC Device Symbolic Name................................38
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6.6.3 FC Device IP Address........................................38
6.6.4 FC Device IPA...............................................38
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................................................39
6.7.3 Assigned ID.................................................39
6.7.4 Space_Identifier............................................39
6.8 Discovery Domain Registration Attributes....................39
6.8.1 iSNS Discovery Domain Attribute Summary.....................40
6.8.2 DD Set ID Keyed Attributes..................................40
6.8.2.1 Discovery Domain Set ID (DDS ID)............................40
6.8.2.2 Discovery Domain Set Symbolic Name..........................40
6.8.2.3 Discovery Domain Set Member.................................40
6.8.3 DD ID Keyed Attributes......................................41
6.8.3.1 Discovery Domain ID (DD ID).................................41
6.8.3.2 Discovery Domain Symbolic Name..............................41
6.8.3.3 Discovery Domain FCIP Member................................41
6.8.3.4 Discovery Domain iSCSI Node Member..........................41
6.8.2.5 Discovery Domain iFCP Node Member...........................41
6.9 Vendor-Specific and User-Specific Attributes................41
7. iSNSP Message Format........................................42
7.1 iSNS PDU Header.............................................42
7.1.1 iSNSP Version...............................................42
7.1.2 iSNSP Function ID...........................................42
7.1.3 iSNSP PDU Length............................................42
7.1.4 iSNSP Flags.................................................42
7.1.5 iSNSP Transaction ID........................................43
7.1.6 iSNSP Sequence ID...........................................43
7.2 iSNS Message Segmentation and Reassembly....................43
7.3 iSNS Message Payload........................................43
7.3.1 Attribute Value 4-Byte Alignment............................44
7.4 iSNSP Response Error Codes..................................44
7.5 Message Authentication......................................45
7.7 Registration and Query Messages.............................46
7.7.1 Source Attribute (Query Only)...............................47
7.7.2 Key Attributes..............................................47
7.7.3 Delimiter Attribute.........................................48
7.7.4 Operating Attributes........................................48
7.7.4.1 Operating Attributes for Query and Get Next Requests........48
7.7.5 Registration and Query Message Types........................48
7.7.5.1 Register Device Attribute Request (RegDevAttr)..............48
7.7.5.1.1 Update Flag................................................49
7.7.5.2 Device Attribute Query Request (DevAttrQry).................50
7.7.5.3 Device Get Next Request (DevGetNext)........................50
7.7.5.4 Deregister Device Request (DeregDev)........................51
7.7.5.5 SCN Register Request (SCNReg)...............................51
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7.7.5.6 SCN Deregister Request (SCNDereg)...........................52
7.7.5.7 SCN Event (SCNEvent)........................................52
7.7.5.8 State Change Notification (SCN).............................53
7.7.5.9 DD Register (DDReg).........................................54
7.7.5.10 DD Deregister (DDDereg).....................................55
7.7.5.11 DDS Register (DDSReg).......................................55
7.7.5.12 DDS Deregister (DDSDereg)...................................56
7.7.5.13 Entity Status Inquiry (ESI).................................56
7.7.5.14 Name Service Heartbeat (Heartbeat)..........................57
7.7.5.15 Request Network Time (RqstTime).............................57
7.7.5.16 Request Switch ID (RqstSwId)................................57
7.7.5.17 Release Switch ID (RlseSwId)................................58
7.7.5.18 Get Switch IDs (GetSwIds)...................................58
7.8 Response Messages...........................................58
7.8.1 Error Code..................................................59
7.8.2 Key Attributes in Response..................................60
7.8.3 Delimiter Attribute in Response.............................60
7.8.4 Operating Attributes in Response............................60
7.8.5 Registration and Query Message Types........................60
7.8.5.1 Register Device Attribute Rsp (RegDevRsp)...................61
7.8.5.2 Device Attribute Query Response (DevAttrQryRsp).............61
7.8.5.3 Device Get Next Response (DevGetNextRsp)....................61
7.8.5.4 Deregister Device Response (DeregDevRsp)....................61
7.8.5.5 SCN Register Response (SCNRegRsp)...........................62
7.8.5.6 SCN Deregister Response (SCNDeregRsp).......................62
7.8.5.7 SCN Event Response (SCNEventRsp)............................62
7.8.5.8 SCN Response (SCNRsp).......................................62
7.8.5.9 DD Register Response (DDRegRsp).............................62
7.8.5.10 DD Deregister Response (DDDeregRsp).........................62
7.8.5.11 DDS Register Response (DDSRegRsp)...........................63
7.8.5.12 DDS Deregister Response (DDSDeregRsp).......................63
7.8.5.13 Entity Status Inquiry Response (ESIRsp).....................63
7.8.5.14 Request Network Time Response (RqstTimeRsp).................63
7.8.5.15 Request Switch ID Response (RqstSwIdRsp)....................64
7.8.5.16 Release Switch ID Response (RlseSwIdRsp)....................64
7.8.5.17 Get Switch IDs Response (GetSwIdRsp)........................64
8. Security Considerations.....................................65
8.1 Data Integrity and Authentication...........................65
8.2 Confidentiality.............................................65
8.3 Security Model..............................................65
9. References..................................................65
10. Author's Addresses..........................................67
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
Gibbons, Tseng, Monia Standards Track 5
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1. Abstract
This document provides a generic framework centering around use of
the iSNS for discovery and management of storage entities in an
enterprise-scale IP storage network. iSNS is an application that
stores client attributes and monitors the availability and
reachability of storage assets in an integrated IP storage network.
Due to its role as a consolidated information repository, iSNS
provides for more efficient and scalable management of IP storage
assets.
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 IP-based storage networks. 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 slaves 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, iFCP, and/or FCIP
protocols as needed; an iSNS implementation MAY provide support for
any one, two, or all three of these protocols as desired by the
implementer. Implementation requirements within each of these
protocols is further discussed in section 5. Although use of iSNS is
optional for iSCSI and FCIP, these protocols will benefit from iSNS
as the number of devices in the storage network increases.
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
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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 devices 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.
3.2 iSNS Functional Components
There are three main functional components of the iSNS:
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 and Fibre Channel
Autonomous Regions (AR's), when required.
3.2.2 Discovery Domain and Login Control Service
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iSNS April 2001
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 provide enhanced security. 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 Hard Zoning
functionality in a Fibre Channel network.
Login Control allows targets to "slave" 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, Port Name (iFCP), or
Fully Qualified Domain Name (FCIP). 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.
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 authorized, a target can upload its own Login Control list. This
is accomplished using the RegDevDD message and listing the iSCSI
Name of each initiator to be registered in the Target's DD.
Devices that do not belong to any Discovery Domain SHALL NOT be
accessible to any other device (except the management station).
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 any other devices
in the iSNS database.
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
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iSNS April 2001
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.
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.
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iSNS April 2001
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.
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 7.7.5.14). 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
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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
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 11
iSNS April 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 12
iSNS April 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 / | | FCIP |
| | | FC /iSNS | |Switch/iSNS | | Gateway |
| | |Gtwy/Server| | /Server| | |
| | +----+------+ +-+-------+--+ +----+----+
| | | | | |
+----+----+ +----+---+ +---+----+ +----+-+ +---+----+ +---+----+
| iSCSI | | iSCSI | | Fibre | | FC | | Fibre | | Fibre |
|Initiator| | Target | |Channel | |Device| |Channel | |Channel |
+---------+ +--------+ |Network | +------+ |Network | |Network |
+--------+ +--------+ +--------+
4. iSNS Object Model
iSNS provides the framework for the registration and discovery of
iSCSI devices, Fibre Channel-based devices using iFCP, and FCIP
tunnel endpoint gateways. This architecture defines common objects
that can be used to represent components referenced by each of these
three 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 13
iSNS April 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 (iFCP and iSCSI Only)
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 shouldnt 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 DDs.
DDSs may contain one or more DDs. Similarly, each DD can be a
member of one or more DDSs. DDSs 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 14
iSNS April 2001
+--------------+ +-----------+
| NETWORK |1 *| |
| ENTITY |----| PORTAL |
| | | |
+--------------+ +-----------+
| 1 *\
| \<==For FCIP Only
| \
| * *\
+-----------+ +--------------+ +-----------+ +-----------+
| FC |1 *| STORAGE |* *| DISCOVERY |* *| DISCOVERY |
| DEVICE |----| NODE |----| DOMAIN |----| DOMAIN |
|(iFCP Only)| |(iFCP & iSCSI)| | | | SET |
+-----------+ +--------------+ +-----------+ +-----------+
* represents 0 to many possible relationships
5. iSNS Implementation Requirements
iSNS can be implemented with features to support any combination of
the following protocols: iSCSI, iFCP, and FCIP. Implementation of
support for any or all 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 15
iSNS April 2001
REQUIRED REQUIRED
Object Attribute to Implement to Use
------ --------- ------------ --------
NETWORK ENTITY Entity Identifier * *
Entity Type * *
Management IP Address
Timestamp *
Entity Certificate *
PORTAL IP Address * *
TCP/UDP Port * *
Portal Symbolic Name *
ESI Interval *
STORAGE NODE iSCSI Name * *
Node Type * *
Alias/Symbolic Node Name *
Node Certificate *
SCN Event Bitmap *
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 16
iSNS April 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 Type
| 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
- 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.
| - Entity Status Inquiry interval
| | If 0, no ESI is used to this Portal
| - Portal Symbolic Name
|
- STORAGE NODE (1 - m per ENTITY)
|
- iSCSI Name
- Node Type (initiator / target / ...)
- Alias/Symbolic Node Name
- Node Certificate
- SCN Event Bitmap
Indicates current SCN state
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 17
iSNS April 2001
+----------------------------------------------------------------+
| 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" |
| -Type: iSCSI | | -Type: 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 18
iSNS April 2001
+---------------------------------------------------------------+
| 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" |
| -Type: 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 19
iSNS April 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
Request Network Time RqstTime 0x0010
NOT USED 0x0011-0x0013
RESERVED 0x0014-0x8000
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-0x800F
Request Net Time Rsp RqstTimeRsp 0x8010
NOT USED 0x8011-0x8013
RESERVED 0x8014-0xFFFF
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 20
iSNS April 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 Type * *
Management IP Address
Timestamp *
Entity Certificate *
PORTAL IP Address * *
TCP/UDP Port * *
Portal Symbolic Name *
ESI Interval *
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 *
Node Certificate *
SCN Event Bitmap *
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
The iSNS attributes used to represent iFCP Storage Systems are shown
and described in the following figure:
- iFCP NETWORK ENTITY
|
Gibbons, Tseng, Monia Standards Track 21
iSNS April 2001
- 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 Type
| 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.
- 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
|
- 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 Descriptor
- FC FC-4 Features
- Node Certificate
- SCN Bitmap
- SCN Event Bitmap
Indicates current SCN state
- FC DEVICE (1 - m per ENTITY)
|
- Node Name (WWNN)
- Node Type (initiator / target / ...)
- Alias/Node Symbolic Name
- FC Node IP-Address
- FC Node IPA
5.2.3 iFCP Attribute Requirements
Gibbons, Tseng, Monia Standards Track 22
iSNS April 2001
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.
+--------------------------------------------------------+
| IP Network |
+--------+-----------------+-----------------------------+
| |
+-+------+------+---+------+------+----------------------+
| | PORTAL | | PORTAL | NETWORK ENTITY |
| | -IP Addr 1 | | -IP Addr 2 | -Entity ID (FQDN): |
| | -TCP Port 1 | | -TCP Port 2 | gtwy1.foo.com |
| +-----+ +-----+ +-----+ +-----+ -Type: 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 |
| | | |
+-------------+ +--------------------+
Gibbons, Tseng, Monia Standards Track 23
iSNS April 2001
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.
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
Request Network Time RqstTime 0x0010
Request Switch ID RqstSwId 0x0011
Release Switch ID RlseSwId 0x0012
Get Switch IDs GetSwIds 0x0013
RESERVED 0x0014-0x8000
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-0x800F
Gibbons, Tseng, Monia Standards Track 24
iSNS April 2001
Request Net Time Resp RqstTimeRsp 0x8010
Request Switch ID Resp RqstSwIdRsp 0x8011
Release Switch ID Resp RlseSwIdRsp 0x8012
Get Switch IDs GetSwIdRsp 0x0013
RESERVED 0x8014-0xFFFF
5.3 FCIP Requirements
Use of iSNS in support of FCIP is OPTIONAL. iSNS MAY be used to
provide dynamic tunnel endpoint discovery. iSNS MAY also be used to
allocate DOMAIN_ID addresses, in an FCIP/Fibre Channel fabric
implementation with multiple Autonomous Regions.
5.3.1 Required Attributes for Support of FCIP
The following lists attributes used in support of FCIP. Attributes
indicated in the REQUIRED TO IMPLEMENT column MUST be supported by
the iSNS server. Attributes indicated in the REQUIRED TO USE column
MUST be supported by an FCIP gateway that elects to use the iSNS for
dynamic tunnel endpoint discovery.
REQUIRED REQUIRED
Object Attribute to Implement to Use
------ --------- ------------ --------
NETWORK ENTITY Entity Identifier * *
Entity Type * *
Management IP Address
Timestamp *
Entity Certificate *
SCN Event Bitmap *
PORTAL IP Address * *
TCP/UDP Port * *
Portal Symbolic Name *
ESI Interval *
5.3.2 Attribute Descriptions for FCIP Gateways
The iSNS attributes used to represent FCIP gateways are shown and
described in the following figure:
Gibbons, Tseng, Monia Standards Track 25
iSNS April 2001
- FCIP 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 Type
| Indicates this is an FCIP registration
- Mgt IP-Address
| If it is not registered then in-band management
| is assumed.
- Timestamp
| Last registration update / status inquiry received
- Entity Certificate
| X.509 certificate bound to the Entity (FQDN)
- SCN Event Bitmap
| Indicates current SCN state
- PORTAL (1 - n per ENTITY)
|
- Index
- IP-Address
- TCP/UDP Port
| The IP-Addr and Port combined uniquely
| define a portal.
- Portal Symbolic Name
- Entity Status Inquiry Interval
0 if no status inquiry is used
5.3.3 Example FCIP Object Model Diagram
The following diagram depicts FCIP gateways stored in the iSNS. In
FCIP, the iSNS is only used for tunnel endpoint discovery.
Therefore, no information about the storage end nodes are registered
in the iSNS, and the STORAGE NODE and FC DEVICE objects are not
applicable.
+----------------------------------------------------------------+
| IP Network |
+-------------+-------------------------+----------------+-------+
| | |
+-----+-------+------+----+ +-+------+------+--+------+-----+-+
| | PORTAL | | | | PORTAL | | PORTAL | |
| | -IP Addr 1 | | | | -IP Addr 2 | | -IP Addr 3 | |
| | -TCP Port 1 | | | | -TCP Port 2 | | -TCP Port 3| |
| +--------------+ | | +-------------+ +------------+ |
| | | |
| NETWORK ENTITY | | NETWORK ENTITY |
| -Entity ID (FQDN): | | -Entity ID (FQDN): |
| "Tunnelgtwy1.foo.com" | | "Tunnelgtwy2.bar.com" |
| -Type: FCIP | | -Type: FCIP |
+-------------------------+ +---------------------------------+
Gibbons, Tseng, Monia Standards Track 26
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5.3.4 Required Commands and Response Messages for Support of FCIP
The following tables display iSNS messages and responses that are
used to support FCIP. Messages indicated in the REQUIRED TO
IMPLEMENT column MUST be supported by the iSNS server used to
support FCIP. Messages indicated in the REQUIRED TO USE column MUST
be supported by the FCIP gateway that elects to use the iSNS.
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
Request Network Time RqstTime 0x0010
Request Switch ID RqstSwId 0x0011
Release Switch ID RlseSwId 0x0012
Get Switch IDs GetSwIds 0x0013
RESERVED 0x0014-0x8000
The following are iSNSP response messages in support of FCIP:
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-0x800F
Gibbons, Tseng, Monia Standards Track 27
iSNS April 2001
Request Net Time Resp RqstTimeRsp 0x8010
Request Switch ID Resp RqstSwIdRsp 0x8011
Release Switch ID Resp RlseSwIdRsp 0x8012
Get Switch IDs Resp GetSwIdsRsp 0x8013
RESERVED 0x8014-0xFFFF
5.4 Attribute Descriptions for Discovery Domain Registration
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:
- Entity Identifier: this places the FCIP gateway in the
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
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. Discovery Domains are described
in Section 3.2.2.
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.
Gibbons, Tseng, Monia Standards Track 28
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6.1 iSNS Attribute Summary
The following table lists all iSNSP message attributes for device
registration and queries:
Gibbons, Tseng, Monia Standards Track 29
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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 Type 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
* Entity Certificate var 5 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
* Portal Certificate var 20 16,17 @|1|16,17|32|64
# iSCSI Name 4-256 32 1% @|1|16,17|32|33
& 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 Descriptors 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
# 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
FC-4 Type Code 4 128 Query Key only
Preferred ID 4 130 Switch ID msgs only
Assigned ID 4 131 Switch ID msgs only
Space_Identifier 0-256 132 Switch ID msgs only
* User Specific iSNS Srvr var - tags in range 256-383
* User Specific Entity var - tags in range 384-511
* User Specific Portal var - tags in range 512-639
* User Spec iSCSI Node var - tags in range 640-767
* User Spec iFCP Node var - tags in range 768-895
* User Spec iFCP FC Node var - tags in range 896-1023
* User Specific FCIP var - tags in range 1024-1151
* User Specific DD var - tags in range 1152-1279
* Vendor Spec iSCSI Node var - tags in range 1280-1407
* Vendor Spec iFCP Node var - tags in range 1408-1535
* Vendor Spec FCIP var - tags in range 1536-1163
* Vendor-Specific var - -vendor defined-
RESERVED 2048-65535
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The following is a description of the columns used in the above
table:
Attribute Type (T)
--------------------------------------------------------------
# : Required key for object registration.
^ : 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.
@ : 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 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.
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6.2.1. Entity Identifier (EID)
The Entity Identifier is a variable length identifier that uniquely
identifies each entity registered in the iSNS. The 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 iSNS:.
6.2.2 Entity Type
Entity Type is a required 4-byte attribute that indicates the type
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
3 FCIP
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, and indicates the time the client
registration occurred, 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 Entity Certificate
This attribute contains an X.509 certificate that is bound to the
NETWORK ENTITY of the iSNS client, and is optional to implement.
For example, in FCIP, this X.509 certificate may have the Fully
Qualified Domain Name of the FCIP gateway device. 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
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to set up the TLS association between the iSNS client and server, as
well as to key the authentication block in the iSNSP.
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
The TCP/UDP port of the PORTAL through which a STORAGE NODE can
transmit and receive storage data. This required field is provided
by the iSNS client. Byte 0 and 1 represent the port number. Bit 0
of byte 2 (bit 17) represents the port type. If bit 17 is set then
the port type is UDP, otherwise it is TCP. All other bits in byte 2
and 3 are reserved. If the value is 0, then the port number is the
implied canonical port number and type of the protocol indicated by
the associated Entity Type.
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 an entity 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 after having
sent an implementation dependent number of ESI messages, then the
entity shall be deregistered.
If the iSNS is unable to support ESI messages, it SHALL reject the
ESI request by returning a "ESI Not Available" error code. The
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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 Portal Certificate
This attribute contains an X.509 certificate that is bound to the
PORTAL of the iSNS client, and is optional to implement. 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 PORTAL. 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.
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 16-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.
Bit Field Node Type
--------- ---------
0 (Lsb) Target
1 Initiator
All Others RESERVED
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.
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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 DEVICE REGISTRATION PARAMETERS
3 DEVICE ADDED
4 DEVICE 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
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
Gibbons, Tseng, Monia Standards Track 35
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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 256 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.
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
Gibbons, Tseng, Monia Standards Track 36
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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
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 DEVICE REGISTRATION PARAMETERS
3 DEVICE ADDED
4 DEVICE REMOVED
All others reserved.
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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.
6.6 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.
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
Gibbons, Tseng, Monia Standards Track 38
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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.
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 and possibly FCIP. 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 clients can be placed into Discovery Domains, which are areas
of control. 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 DDs.
Gibbons, Tseng, Monia Standards Track 39
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Additionally, Discovery Domains can be a member of one or more
Discovery Domain Sets (DDS). Discovery Domain Sets can be
administratively enabled or disabled. Only Discovery Domains in an
enabled Discovery Domain Set are active / enforced by the iSNS.
6.8.1 iSNS Discovery Domain Attribute Summary
The following table lists the iSNSP DD attributes:
Attribute Name Size(bytes) ID Reg Key Query Key
-------------- ----------- -- ------- ---------
DD_Set ID 4 101 @ 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* 32,64,101,104
DD_Symbolic Name 4-256 105 104 104
DD FCIP Member 0-256 106 104 104
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
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 placed into
DDS 0.
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 Invalid Registration 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 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.
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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
Invalid Registration 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 FCIP Member
The Entity Identifier of an FCIP iSNS client that is a member of the
DD. The DD may have a list of 0 to n members. Registering the
Entity Identifier of the iSNS client represents DD membership.
6.8.3.4 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.
6.8.2.5 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 and User-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
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
Gibbons, Tseng, Monia Standards Track 41
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the OUI in the vendor-specific or user-specific attribute field, and
be able to execute vendor-specific handling of the attribute.
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 iSNS 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, iFCP, and/or FCIP) for a mapping of the
FUNCTION_ID value to the iSNSP Command or Response message. All
PDU's comprising an iSNSP message must have the same FUNCTION_IDand
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
Gibbons, Tseng, Monia Standards Track 42
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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 RegDevAttr)
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 iSNS 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.
The authentication operation described in section 7.5 SHALL be
performed on a per-PDU basis.
7.3 iSNS 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
Gibbons, Tseng, Monia Standards Track 43
iSNS April 2001
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
For iSNS response messages sent by the iSNS server to the client, a
4-byte ERROR CODE field is included as the first field in the iSNSP
PAYLOAD. This field contains 0x00000000 (NO ERROR) if the original
iSNSP request message was processed normally by the iSNS server.
Error Code Error Description
---------- -----------------
0 No Error
1 Unknown Error
2 Message Format Error
3 Invalid Registration
4 Invalid Registration Update
5 Invalid Query
6 Authentication Unknown
7 Authentication Absent
8 Authentication Failed
9 No Such Entry
10 Version Not Supported
Gibbons, Tseng, Monia Standards Track 44
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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 Entity Status Inquiry (ESI) Not Available
19 SWITCH_ID not available
20 SWITCH_ID not allocated
21 Attribute not Implemented
For iSNS State Change Notification message and Request Network Time
Response messages, a 4-byte TIMESTAMP field is included. The
TIMESTAMP is a 4-byte unsigned, fixed-point integer giving the
number of seconds since 00:00:00 GMT on January 1, 1970.
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
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:
Gibbons, Tseng, Monia Standards Track 45
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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.
7.7 Registration and Query Messages
The iSNSP registration and query message payloads contain a list of
attributes, and have the following format:
Gibbons, Tseng, Monia Standards Track 46
iSNS April 2001
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.
7.7.1 Source Attribute (Query Only)
The source attribute is used to identify the iSNS client to the iSNS
server for query messages. The source attribute is an attribute
that uniquely identifies the source of the message. Valid source
attribute types are shown below.
Valid Source Attributes
-----------------------
Entity Identifier (FCIP Only)
iSCSI Name (iSCSI only)
iFCP Node Port WWN (iFCP only)
The source attribute is used to bind the scope of a query 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.
7.7.2 Key Attributes
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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.
7.7.3 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.
7.7.4 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.
7.7.4.1 Operating Attributes for Query and Get Next Requests
A length value of 0 in an Operating Attribute TLV is valid for query
request and get next messages where the iSNS will be returning
matching attribute values in the response message. In this case the
Operating Attributes indicate the desired attributes to be returned
in the response and therefore do not require values. The response
message will contain valid values for the Operating Attributes if
the Key Attributes in the query or get next are matched.
7.7.5 Registration and Query Message Types
The following describes each query and message type.
7.7.5.1 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.
Gibbons, Tseng, Monia Standards Track 48
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For the initial network entity registration a Key Attribute is not
required, but is required for update registrations to existing
objects.
The operating attributes are 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.
One RegDevAttr message can contain attributes for Entity, Portal,
and Node objects if they are contained in the same Entity. When the
registration contains attributes for the Entity, Portal, and Node
objects together, 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.
When a registration of a Portal, Node or Port is performed, the
appropriate associations between objects will be created in the
iSNS.
A operating attribute TLV with a length value of 0 is valid for
initial client registration when the iSNS is being used to assign a
unique identifier to the client.
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 value(s), or be added to existing value(s)
of the specified operating attribute.
7.7.5.1.1 Update Flag
The Update Flag, contained in the message header FLAGS field,
indicates the RegDevAttr message is an update to an existing entry.
If the key attributes match an existing object in the iSNS directory
database, and the Update bit in the flags field is not set, then the
registration will replace the existing registration. The existing
object shall be de-registered. A new registration will 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
Gibbons, Tseng, Monia Standards Track 49
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values or add additional attributes in the key entry. Existing
associations between objects will be maintained. If the Update bit
is set and the registration would cause a change in associations,
then the error Invalid Registration Update 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.
7.7.5.2 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 7.7.1. 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
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 Type
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.
7.7.5.3 Device Get Next Request (DevGetNext)
The DevGetNext message type is 0x0003. This message provides the
iSNS client with the means to sequentially retrieve Entity
Identifiers, IP Addresses, iSCSI Names, Node Names and Port Names
from devices in DDs to which the client has access.
The Source attribute of the DevGetNext message is as defined in
Section 7.7.1. The source is used to scope the Get Next process to
Gibbons, Tseng, Monia Standards Track 50
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the Discovery Domains that the source attribute is a member of. It
is the Entity Identifier, iSCSI Name, Node Name, Port Name, or the
IP-Address of the client performing the query.
The Key Attribute follows the source attribute in the message
payload. The Key Attribute is an Entity Identifier, iSCSI Name, IP
Address, Node Name, or Port Name. If the key length value entered
is zero, signifying an empty key value field, the first accessible a
Entity Identifier, iSCSI Name, IP Address, Node Name, or Port Name
instance shall be returned to the client.
There are no Delimiter or Operating Attributes in the DevGetNext
request message.
7.7.5.4 Deregister Device Request (DeregDev)
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 7.7.1. 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.
7.7.5.5 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 network entity 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 port is a member of.
The SCNReg request message payload contains a Source Attribute, Key
Attribute(s), and Operating Attributes. The Source attribute of the
SCNReg message is as defined in Section 7.7.1. Valid Key Attributes
for an SCNReg are shown below:
Gibbons, Tseng, Monia Standards Track 51
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Valid Key Attributes for SCNReg
--------------------------------
iSCSI Name
Port WWN (iFCP Only)
Entity Identifier (FCIP Only)
The network entity nodes matching the Key Attributes are registered
to receive SCNs.
The Operating Attributes section contains the Entity Event Bitmap
attribute. The bitmap indicates the INTERESTED EVENT TYPE FLAGS
that the network entity is registering for.
Section 6.5.12 describes each flag used in the EVENT TYPE FLAGS
field.
7.7.5.6 SCN Deregister Request (SCNDereg)
The SCNDereg message type is 0x0006. The SCNDereg message allows an
iSNS client to deregister a network entity to receive 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 7.7.1. Valid Key Attributes for an SCNDereg
are shown below:
Valid Key Attributes for SCNDereg
--------------------------------
Entity Identifier (FCIP only)
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.
7.7.5.7 SCN Event (SCNEvent)
The SCNEvent message type is 0x0007. The SCNEvent is a special
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 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
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 the SCNEvent.
Gibbons, Tseng, Monia Standards Track 52
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The format of the SCNEvent message is shown below:
MSb LSb
31 0
+----------------------------------------+
| Source Attribute |
+----------------------------------------+
| Source Event Bitmap |
+----------------------------------------+
The Source Attribute is the object that caused the SCN to be
generated. The Source Attribute can be an Entity Identifier, iSCSI
Name, Node Name or Port Name.
The Source Event Bitmap indicates the event that caused the SCN to
be generated. The Event Bitmap is a 32 bit field, with the
following definitions:
Bit Field Flag Description
--------- ----------------
0 CHANGE IN DD MEMBERSHIP
1 CHANGE IN NETWORK
2 CHANGE IN DEVICE REGISTRATION PARAMETERS
3 DEVICE ADDED
4 DEVICE REMOVED
All Others Reserved
7.7.5.8 State Change Notification (SCN)
The SCN message type is 0x0008. The SCN is a special message
generated by the iSNS which allows a registered network 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 entity will be notified about are
based on the value of the Entity Event Bitmap, as described in
Section 6.8.
The format of the SCN message is shown below:
Gibbons, Tseng, Monia Standards Track 53
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MSb LSb
31 0
+----------------------------------------+
| Destination Attribute |
+----------------------------------------+
| Timestamp |
+----------------------------------------+
| Source Attribute[1] |
+----------------------------------------+
| Source Event Bitmap[1] |
+----------------------------------------+
| Source Attribute [2](if present) |
+----------------------------------------+
| Source Event Bitmap [2](if present) |
+----------------------------------------+
| Source Attribute [3](if present) |
+----------------------------------------+
| Source Event Bitmap [3](if present) |
+----------------------------------------+
| . . . |
+----------------------------------------+
The Destination Attribute is the object that is receiving the SCN.
The Destination Attribute can be an Entity Identifier, iSCSI Name,
Node Name or Port Name.
The Timestamp field indicates the time the SCN Event was generated.
The timestamp is a 4-byte unsigned, fixed-point integer giving the
number of seconds since 00:00:00 GMT on January 1, 1970.
The Source Attribute is the object that caused the SCN to be
generated. The Source Attribute can be an Entity Identifier, iSCSI
Name, Node Name or Port Name.
The Source Event Bitmap indicates the event that caused the SCN to
be generated. The Event Bitmap is a 32 bit field, with the
following definitions:
Bit Field Flag Description
--------- ----------------
0 CHANGE IN DD MEMBERSHIP
1 CHANGE IN NETWORK
2 CHANGE IN DEVICE REGISTRATION PARAMETERS
3 DEVICE ADDED
4 DEVICE REMOVED
All Others Reserved
7.7.5.9 DD Register (DDReg)
The DDReg message type is 0x0009. This message allows an iSNS
client to create a new Discovery Domain (DD), update an existing DD
Symbolic Name, or add DD members.
Gibbons, Tseng, Monia Standards Track 54
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DDs are uniquely defined using DD_IDs. DD registration attributes
are described in section 6.8.
The DDReg message payload contains the Source Attribute, Key
Attributes and Operating Attributes. The Source attribute of the
DDReg message is as defined in Section 7.7.1.
For the initial DD registration a Key Attribute is not required, but
is required for update registrations to existing DDs. The Key
Attribute for a DDReg message is the DD ID for the domain being
updated. If the key attribute matches an existing DD, then the DD
will be updated with the Operating Attributes.
The operating attributes can contain the DD ID and DD Symbolic Name
for a new registration. If the DD ID is to be assigned by the iSNS
then the DD ID will be of length 0 and the assigned value shall be
returned in the response.
The Operating Attributes also contain the iSCSI Node Identifier,
iFCP WWPN, or FCIP Entity_ID of iSNS clients to be added to the DD.
7.7.5.10 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 7.7.1.
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 No Such Entry
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 the operating attributes do not match DD
members, then the error code No Such Entry will be returned, and
no DD members shall be removed.
7.7.5.11 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.
Gibbons, Tseng, Monia Standards Track 55
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DDSs are uniquely defined using DDS_IDs. DDS registration
attributes are described in section 6.8.
The DDSReg message payload contains the Source Attribute, Key
Attributes and Operating Attributes. The Source attribute of the
DDSReg message is as defined in Section 7.7.1.
For the initial DDS registration a Key Attribute is not required,
but is required for update registrations to existing DDSs. The Key
Attribute for a DDSReg message is the DDS ID for the set being
updated. If the key attribute matches an existing DDS, then the DDS
will be updated with the Operating Attributes.
The operating attributes can contain the DDS ID, DDS Symbolic Name,
and DDS Status for a new registration. If the DDS ID is to be
assigned by the iSNS then the DDS ID will be of length 0 and the
assigned value shall be returned in the response.
The Operating Attributes also contain the DD_IDs of Discovery
Domains to be added to the DDS.
7.7.5.12 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 DDs from an existing DDS.
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 7.7.1.
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 No
Such Entry 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 the
operating attributes do not match DDS members, then the error code
No Such Entry will be returned.
7.7.5.13 Entity Status Inquiry (ESI)
The ESI message type is 0x000D. This message is used to verify that
an individual iSNS client is reachable and available.
The ESI response message payload contains the destination attribute
specifying the Entity Identifier of the iSNS client.
Gibbons, Tseng, Monia Standards Track 56
iSNS April 2001
If the iSNS client fails to respond to three consecutive ESI
messages, then the iSNS shall remove that client from the iSNS
database and trigger the appropriate State Change Notifications, if
any.
7.7.5.14 Name Service Heartbeat (Heartbeat)
This optional message is regularly issued by the iSNS server to a
broadcast or multicast address at an administratively-configured
time interval. The payload of this message contains a single 4-byte
unsigned integer field containing the heartbeat period, the number
of seconds between each successive heartbeat message. This
information is NOT in TLV format. The contents of the remainder of
this message are vendor-specific.
This message allows iSNS clients listening to the broadcast or
multicast address to discover the IP address of the iSNS server by
examining the source IP address of the message. 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.
7.7.5.15 Request Network Time (RqstTime)
The RqstTime message type is 0x0010. This is a special message that
returns the network time as stored in the iSNS. The iSNS uses NTP
to obtain and maintain the network time provided in the RqstTime
message.
There are no Key or Operating attributes in this message.
7.7.5.16 Request Switch ID (RqstSwId)
The RqstSwId message type is 0x0011. This optional message is used
for FCIP and iFCP Transparent Mode to allocate non-overlapping
SWITCH_ID values between 1 and 239. In the case of FCIP, the iSNS
client may be an address assignment authority for an Autonomous
Region of a Fibre Channel fabric. In the case of iFCP, 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 57
iSNS April 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 an SWITCH_ID value has been allocated by the iSNS server for a
give Space_Identifier, that SWITCH_ID value 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.
7.7.5.17 Release Switch ID (RlseSwId)
The RlseSwId message type is 0x0012. This optional message may be
used by FCIP and 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.
7.7.5.18 Get Switch IDs (GetSwIds)
The GetSwIds message type is 0x0013. This optional message is used
to learn the currently-used SWITCH_ID values allocated 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 7.7.1.
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.
7.8 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 58
iSNS April 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.
7.8.1 Error Code
The iSNSP response message payloads contain a 4-byte ERROR CODE
field. If the operation completed successfully the Error Code field
will contain No Error, represented by 0x00000000. The list of valid
Error Codes are shown below:
Gibbons, Tseng, Monia Standards Track 59
iSNS April 2001
Error Code Error Description
---------- -----------------
0 No Error
1 Unknown Error
2 Message Format Error
3 Invalid Registration
4 Invalid Registration Update
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 Client Status Inquiry Not Available
19 DOMAIN_ID not available
7.8.2 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.
7.8.3 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.
7.8.4 Operating Attributes in Response
The Operating Attributes in a response are the results related to
the iSNS registration or query operation being performed.
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.
7.8.5 Registration and Query Message Types
The following describes each query and message type.
Gibbons, Tseng, Monia Standards Track 60
iSNS April 2001
7.8.5.1 Register Device Attribute Rsp (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 No Error 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.
7.8.5.2 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 No Error is returned. If an
error occurred then the appropriate code will be returned.
For a successful query result, the DevAttrQryRsp Operating Attribute
field will contain the set of results that match the original
DevAttrQry Key Attributes.
7.8.5.3 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 No Error is returned. If an
error occurred then the appropriate code will be returned.
The Key Attribute field contains the next key, in lexicographical
order, after the Key Attribute used in the DevGetNext message.
The Operating Attribute field contains the same attributes as were
in the DevGetNext message. The values of the Operating Attributes
are the attribute values associated with the key returned.
7.8.5.4 Deregister Device Response (DeregDevRsp)
The DeregDevRsp message type is 0x8004. If the DeregDev operation
completed successfully then the code of No Error is returned. If
an error occurred then the appropriate code will be returned.
Gibbons, Tseng, Monia Standards Track 61
iSNS April 2001
The DeregDevRsp message does not contain any key or operating
attributes.
7.8.5.5 SCN Register Response (SCNRegRsp)
The SCNRegRsp message type is 0x8005. If the SCNReg operation
completed successfully then the code of No Error is returned. If
an error occurred then the appropriate code will be returned.
The SCNRegRsp message does not contain any key or operating
attributes.
7.8.5.6 SCN Deregister Response (SCNDeregRsp)
The SCNDeregRsp message type is 0x8006. If the SCNDereg operation
completed successfully then the code of No Error is returned. If
an error occurred then the appropriate code will be returned.
The SCNDeregRsp message does not contain any key or operating
attributes.
7.8.5.7 SCN Event Response (SCNEventRsp)
The SCNEventRsp message type is 0x8007. If the SCNEvent operation
completed successfully then the code of No Error is returned. If
an error occurred then the appropriate code will be returned.
The SCNEventRsp message does not contain any key or operating
attributes.
7.8.5.8 SCN Response (SCNRsp)
The SCNRsp message type is 0x8008. If the SCN operation completed
successfully then the code of No Error is returned. If an error
occurred then the appropriate code will be returned.
The SCNRsp message does not contain any key or operating attributes.
7.8.5.9 DD Register Response (DDRegRsp)
The DDRegRsp message type is 0x8009. If the DDReg operation
completed successfully then the code of No Error 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.
7.8.5.10 DD Deregister Response (DDDeregRsp)
The DDDeregRsp message type is 0x800A. If the DDDereg operation
completed successfully then the code of No Error is returned. If
an error occurred then the appropriate code will be returned.
Gibbons, Tseng, Monia Standards Track 62
iSNS April 2001
If successful, the DD ID of the DD removed or updated during the
DDDereg operation will be returned as an operating attribute of the
message.
7.8.5.11 DDS Register Response (DDSRegRsp)
The DDSRegRsp message type is 0x800B. If the DDSRegRsp operation
completed successfully then the code of No Error 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.
7.8.5.12 DDS Deregister Response (DDSDeregRsp)
The DDSDeregRsp message type is 0x800C. If the DDSDeregRsp operation
completed successfully then the code of No Error is returned. If
an error occurred then the appropriate code will be returned.
If successful, the DDS ID of the DDS removed or updated during the
DDSDereg operation will be returned as an operating attribute of the
message.
7.8.5.13 Entity Status Inquiry Response (ESIRsp)
The ESIRsp message type is 0x800D. This message provides
confirmation that the ESI message was received and processed by the
iSNS client.
The ESIRsp response message payload contains the source attribute of
the iSNS client network entity.
Upon receiving the ESIRsp from the iSNS client, the iSNS server
SHALL update the timestamp attribute for that client.
If the ESI operation completed successfully on the iSNS client then
the code of No Error is returned. If an error occurred then the
appropriate code will be returned.
The ESIRsp message does not contain any key or operating attributes.
7.8.5.14 Request Network Time Response (RqstTimeRsp)
The RqstTimeRsp message type is 0x8010. The format of the
RqstTimeRsp payload is different than other response message
payloads, and is shown below:
Gibbons, Tseng, Monia Standards Track 63
iSNS April 2001
MSb LSb
31 0
+----------------------------------------+
| 4-byte ERROR CODE |
+----------------------------------------+
| 8-byte TIMESTAMP |
+----------------------------------------+
The TIMESTAMP is a 8-byte unsigned, fixed-point integer giving the
number of seconds since 00:00:00 GMT on January 1, 1970. The
Network Time Protocol can be used by the iSNS to generate the
timestamp provided. The iSNS TIMESTAMP shall only be considered to
be locally significant.
7.8.5.15 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.
7.8.5.16 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 SWITCH_ID
not allocated.
The iSNS server and client SHALL use TCP to transmit and receive
RqstSwId, RqstSwIdRsp, RlseSwId, and RlseSwIdRsp messages.
7.8.5.17 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
Gibbons, Tseng, Monia Standards Track 64
iSNS April 2001
IDs from the space requested. The Assigned_ID attributes are listed
in TLV format.
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 6.4. 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). However, there will be many instances where
confidentiality will not be a requirement. 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 6.4.
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
[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,
Gibbons, Tseng, Monia Standards Track 65
iSNS April 2001
draft-bakke-iscsi-slp-00.txt
[iSCSI-NDR] iSCSI Naming and Discovery Requirements,
draft-ietf-ips-iscsi-name-disc-00.txt
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
Gibbons, Tseng, Monia Standards Track 66
iSNS April 2001
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
Jim Hafner
IBM Research
Almaden Research Center K53-B2
650 Harry Road
San Jose, CA 95120-6099
Email: hafner@almaden.ibm.com
Phone: 408-927-1892
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 April 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 "slaved" to the iSNS.
Gibbons, Tseng, Monia Standards Track 69
iSNS April 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: MGMTname1 |
| |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 April 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 April 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 |<--RegDevDD |
|in DDxyz by management | |src: "mgmt.foo.com"|
|station. | |key: "DDxyz ID" |
|*************************/| |Op Attr: |
| | |tag=32: "NAMEabcd" |
| | RegDevDDRsp---->| |
| | 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
iSNS April 2001
|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
| | |******************/|
| | |<--RegDevDD |
| | |src: (tag=1) |
| | | "mgmt.foo.com" |
| | |key: "DDxyz ID" |
| | |tag=32: "NAMEijkl |
| | | |
| | RegDevDDRsp--->|/******************|
| | SUCCESS |"NAMEijkl" has been|
| | |moved to "DDxyz" |
| | |******************/|
| |<-----SCN | |
| |tag=32: "NAMEijkl"| |
| |CHANGE IN DD MEMBERSHIP |
| DevAttrQry----------->| | |
Gibbons, Tseng, Monia Standards Track 73
iSNS April 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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