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Versions: (draft-tseng-dhc-isnsoption) 00 01
02 03 04 05 06 07 08 09 10 11 12 13
RFC 4174
DHC Josh Tseng
Internet Draft Kevin Gibbons
<draft-ietf-dhc-isnsoption-01.txt> Nishan Systems
Expires January 2003 July 2002
DHCP Options for 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].
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-
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as reference material or to cite them other than as "work in
progress."
The list of current Internet-Drafts can be accessed at
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The list of Internet-Draft Shadow Directories can be accessed at
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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
Comments..............................................................1
Abstract..............................................................2
Conventions used in this document.....................................2
1. Introduction......................................................2
2. iSNS Option for DHCP..............................................3
3. Security Considerations...........................................6
4. References........................................................6
5. Author's Addresses................................................7
Full Copyright Statement..............................................8
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DHCP Option Number for iSNS February 2002
Abstract
This document describes the DHCP option to allow iSNS clients
devices using DHCP to automatically discover the location of the
iSNS server. iSNS provides discovery and management capabilities for
iSCSI and Fibre Channel (FCP) storage devices in an enterprise-scale
IP storage network. iSNS provides intelligent storage management
services comparable to those found in Fibre Channel networks,
allowing a commodity IP network to function in a similar capacity as
a storage area network.
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 [RFC2119].
All frame formats are in big endian network byte order. RESERVED
fields SHOULD be set to zero.
This document uses the following terms:
"iSNS Client" - iSNS clients are processes resident in iSCSI and
iFCP devices that initiate transactions with the iSNS server using
the iSNS Protocol.
"iSNS Server" - The iSNS server responds to iSNS protocol query and
registration messages, and initiates asynchronous notification
messages. The iSNS server stores information registered by iSNS
clients.
"iSCSI (Internet SCSI)" - iSCSI is an encapsulation of SCSI for a
new generation of storage devices interconnected with TCP/IP.
"iFCP (Internet Fibre Channel Protocol)" - iFCP is a gateway-to-
gateway protocol designed to interconnect existing Fibre Channel and
SCSI devices using TCP/IP. iFCP maps the existing FCP standard and
associated Fibre Channel services to TCP/IP.
1. Introduction
The Dynamic Host Configuration Protocol provides a framework for
passing configuration information to hosts. Its usefulness extends
to hosts and devices using the iSCSI and iFCP protocols to connect
to block level storage assets over a TCP/IP network.
The iSNS Protocol provides a framework for automated discovery,
management, and configuration of iSCSI and iFCP devices on a TCP/IP
network. It provides functionality similar to that found on Fibre
Channel networks, except that iSNS works within the context of an IP
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DHCP Option Number for iSNS February 2002
network. iSNS thereby provides the requisite storage intelligence
to IP networks that are standard on existing Fibre Channel networks.
Existing DHCP option numbers are not plausible due to the following
reasons:
1) iSNS functionality is distinctly different from other protocols
using existing DHCP option numbers. Specifically, iSNS provides a
significant superset of capabilities compared to typical name
resolution protocols such as DNS. It is designed to support client
devices that allow themselves to be configured and managed from a
central iSNS server.
2) iSNS requires a DHCP option format that provides more than the
location of the iSNS server. The DHCP option number needs to
specify the subset of iSNS services that will be actively used by
the iSNS client.
The DHCP option number for iSNS is used by iSCSI and iFCP devices to
discover the location and role of the iSNS server. The DHCP option
number assigned for iSNS by IANA is <<TBD>>.
2. iSNS Option for DHCP
This option specifies the location of the primary and backup iSNS
servers and the subset of iSNS services that will be used by the
iSNS client.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code = TBD | Length | iSNS Function |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DD Access | Administrative FLAGS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| a1 | a2 | a3 | a4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| b1 | b2 | b3 | b4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The iSNS Option specifies a list of IP addresses used by iSNS
servers.
Length indicates the number of bytes that follow the Length field.
The minimum value for the Length field is 6 in order to account for
the iSNS Function, Discovery Domain Access, and Administrative Flags
field.
iSNS Function is a bitmap field defining the iSNS server's
operational role (i.e., how the iSNS server is to be used). The
iSNS server's role can be as basic as to provide simple discovery
information, or as significant as to provide IKE/IPSec security
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DHCP Option Number for iSNS February 2002
policies and certificates for the use of iSCSI and iFCP devices. The
format of the iSNS Role bit field is shown below:
1 2 3
6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Site-Specific |RESERVED |S|A|E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bit field Significance
--------- ------------
31 Enabled/Disabled
30 Authorization/Discovery Domains
29 Security
28-24 RESERVED
23-16 Site-specific or Vendor-specific use only
Enabled/Disabled: This bit determines the validity of the iSNS Role
field. If this bit is enabled, then the contents of the remainder
of the iSNS Role field are valid. If this bit is disabled, then the
contents of the iSNS Role field are invalid.
Authorization: Indicates the role of the iSNS server in determining
device access authorizations. If disabled, then the function of the
iSNS server is for target discovery purposes only. Discovery
Domains MAY be used to manage the discovery process, but they do not
necessarily indicate authorization to access discovered devices. If
enabled, then Discovery Domain/Zoning features of the iSNS indicate
device access authorizations. Devices in a common DD SHALL be
allowed access to each other if they are successfully authenticated.
Devices not in a common DD shall not be allowed to access each
other.
Security: Indicates whether the iSNS client is to download and use
the security policy configuration stored in the iSNS server. If
enabled, then the AuthMethod and IKE/IPSec policy stored in the iSNS
server SHALL be used by the iSNS client for its own security policy.
If disabled, then the iSNS client SHALL NOT query for its own
security policy attributes in the iSNS server.
Site-Specific: These bits are used to indicate site-specific or
vendor-specific capabilities in the indicated iSNS server.
Discovery Domain Access is a bit field that indicates the types of
iSNS clients that are allowed to modify Discovery Domains. The
format of the DD Access bit field is shown below:
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0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| R | R | if| tf| is| ts| C | E |
+---+---+---+---+---+---+---+---+
Bit field Significance
--------- ------------
7 Enabled/Disabled
6 Control Node
5 iSCSI Target
4 iSCSI Initiator
3 iFCP Target Port
2 iFCP Initiator Port
1 RESERVED
0 RESERVED
Enabled/Disabled: This bit determines the validity of the DD Access
bit field. If this bit is enabled, then the contents of the
remainder of the DD Access field are valid. If this bit is
disabled, then the contents of this field are invalid.
Control Node: Determines whether Control Nodes are allowed to add,
delete, or modify Discovery Domains. If enabled, then Control Nodes
are allowed. If disabled, then Control Nodes are not allowed to
modify Discovery Domains.
iSCSI Target, iSCSI Initiator, iFCP Target Port, and iFCP Initiator
Port: These bits determine whether the respective registered iSNS
client (determined by iSCSI Node Type or iFCP Port Role) is allowed
to add, delete, or modify Discovery Domains. If enabled, then the
respective types of iSNS clients are allowed. If disabled, then
they are not allowed to modify Discovery Domains.
The Administrative Flags field configures the administrative
settings for the iSNS server discovered through the DHCP option.
The format of the Administrative Flags bit field is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Site-Specific | RESERVED |D|M|H|E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bit field Significance
--------- ------------
31 Enabled/Disabled
30 Heartbeat
29 Management SCN's
28 Default Discovery Domain
26-8 RESERVED
7-0 Site-specific or Vendor-specific use only
Enabled/Disabled: This bit determines the validity of the
Administrative Flags field. If this bit is enabled, then the
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contents of the remainder of the Administrative Flags field are
valid. If this bit is disabled, then the contents of this field are
invalid, indicating that iSNS administrative settings are configured
through alternative means other than DHCP.
Heartbeat: Indicates whether the first IP address is the multicast
address for the iSNS heartbeat message. If enabled, then a1-a4
contains the heartbeat multicast address and b1-b4 contains the IP
address of the primary iSNS server, followed by the IP address(es)
of any backup servers. If disabled, then a1-a4 contains the IP
address of the primary iSNS server, followed by the IP address(es)
of any backup servers.
Management SCNs: Indicates whether control nodes are authorized to
register to receive Management SCN's. Management SCN's are a
special class of State Change Notification whose scope is the entire
iSNS database. If enabled, then control nodes are authorized to
register to receive Management SCN's. If disabled, then control
nodes are not authorized to receive Management SCN's (although they
may receive normal SCN's).
Default Discovery Domain: Indicates whether a newly registered
device that is not explicitly placed into a Discovery Domain (DD)
and Discovery Domain Set (DDS) should be automatically placed into a
default DD and DDS. If enabled, then a default DD shall contain all
devices in the iSNS database that have not been explicitly placed
into a DD by an iSNS client. If disabled, then devices not
explicitly placed into a DD are not members of any DD.
3. Security Considerations
DHCP currently provides no authentication or security mechanisms.
Potential exposures to attack are discussed in section 7 of the DHCP
protocol specification [DHCP].
iSNS security considerations are discussed in [iSNS] and [SEC-IPS].
4. References
[DHCP] Droms, R., "Dynamic Host Configuration Protocol", RFC
2131, Bucknell University, March 1997.
[iSCSI] Satran, J., et al., "iSCSI", Internet draft (work in
progress), draft-ietf-ips-iSCSI-13.txt, June 2002
[iFCP] Monia, C., et al., "iFCP - A Protocol for Internet Fibre
Channel Storage Networking", Internet draft (work in
progress), draft-ietf-ips-ifcp-11.txt, May 2002
[iSNS] Tseng, J. et al., "iSNS - Internet Storage Name
Service", Internet draft (work in progress), draft-ietf-
ips-isns-10.txt, May 2002
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DHCP Option Number for iSNS February 2002
[SEC-IPS] Aboba, B., et al., "Securing IP Block Storage
Protocols", draft-ietf-ips-security-13.txt, June 2002
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997
5. Author's Addresses
Josh Tseng
Nishan Systems
3850 North First Street
San Jose, CA 95134-1702
Phone: (408) 519-3749
Email: jtseng@nishansystems.com
Tseng [Page 7]
Internet Storage Name Service (iSNS) November 2001
Full Copyright Statement
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Internet Storage Name Service (iSNS) November 2001
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