Network Working Group C. Monia
Request for Comments: 4174 Consultant
Category: Standards Track J. Tseng
Riverbed Technology
K. Gibbons
McDATA Corporation
September 2005
The IPv4 Dynamic Host Configuration Protocol (DHCP) Option
for the Internet Storage Name Service
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This document describes the Dynamic Host Configuration Protocol
(DHCP) option to allow Internet Storage Name Service (iSNS) clients
to discover the location of the iSNS server automatically through the
use of DHCP for IPv4. iSNS provides discovery and management
capabilities for Internet SCSI (iSCSI) and Internet Fibre Channel
Protocol (iFCP) 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 to that of a
storage area network.
Table of Contents
1. Introduction ................................................. 2
1.1. Conventions Used in This Document ...................... 2
2. iSNS Option for DHCP ......................................... 3
2.1. iSNS Functions Field ................................... 5
2.2. Discovery Domain Access Field .......................... 6
2.3. Administrative Flags Field ............................. 7
2.4. iSNS Server Security Bitmap ............................ 8
3. Security Considerations ...................................... 9
4. IANA Considerations .......................................... 11
Monia, et al. Standards Track [Page 1]RFC 4174 DHCP Option Number for iSNS September 2005
5. Normative References ......................................... 11
6. Informative References ....................................... 11
1. Introduction
The Dynamic Host Configuration Protocol for IPv4 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
network. iSNS thereby provides the requisite storage intelligence to
IP networks that are standard on existing Fibre Channel networks.
Existing DHCP options cannot be used to find iSNS servers for the
following reasons:
a) iSNS functionality is distinctly different from other protocols
using DHCP options. 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.
b) iSNS requires a DHCP option format that provides more than the
location of the iSNS server. The DHCP option has to specify the
subset of iSNS services that may 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 83.
1.1. Conventions Used in This Document
iSNS refers to the Internet Storage Name Service framework, which
consists 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
datatracker.ietf.org