Browse Prior Art Database

Transmission of IPv6 Packets over Token Ring Networks (RFC2470)

IP.com Disclosure Number: IPCOM000003050D
Original Publication Date: 1998-Dec-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 9 page(s) / 20K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

M. Crawford: AUTHOR [+3]

Abstract

This memo specifies the MTU and frame format for transmission of IPv6 packets on Token Ring networks. It also specifies the method of forming IPv6 link-local addresses on Token Ring networks and the content of the Source/Target Link-layer Address option used the Router Solicitation, Router Advertisement, Redirect, Neighbor Solicitation and Neighbor Advertisement messages when those messages are transmitted on a Token Ring network.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 15% of the total text.

Network Working Group M. Crawford

Request for Comments: 2470 Fermilab

Category: Standards Track T. Narten

IBM

S. Thomas

TransNexus

December 1998

Transmission of IPv6 Packets over Token Ring Networks

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 (1998). All Rights Reserved.

1. Introduction

This memo specifies the MTU and frame format for transmission of IPv6

packets on Token Ring networks. It also specifies the method of

forming IPv6 link-local addresses on Token Ring networks and the

content of the Source/Target Link-layer Address option used the

Router Solicitation, Router Advertisement, Redirect, Neighbor

Solicitation and Neighbor Advertisement messages when those messages

are transmitted on a Token Ring network.

Implementors should be careful to note that Token Ring adaptors

assume addresses are in non-canonical rather than canonical format,

requiring that special care be taken to insure that addresses are

processed correctly. See [CANON] for more details.

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 [KWORD].

2. Maximum Transmission Unit

IEEE 802.5 networks have a maximum frame size based on the maximum

time a node may hold the token. This time depends on many factors

including the data signaling rate and the number of nodes on the

ring. Because the maximum frame size varies, implementations must

rely on manual configuration or router advertisements [DISC] to

determine actual MTU sizes. Common default values include

approximately 2000, 4000, and 8000 octets.

In the absence of any other information, an implementation should use

a default MTU of 1500 octets. This size offers compatibility with all

common 802.5 defaults, as well as with Ethernet LANs in an

environment using transparent bridging.

In an environment using source route bridging, the process of

discovering the MAC-level path to a neighbor can yield the MTU for

the path to that neighbor. The information is contained in the

largest frame (LF) subfield of the routing information field. This

field limits the size of the information field of frames to that

destination, a...