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6rd Tunnel MTU
draft-foo-v6ops-6rdmtu-00

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Expired".
Expired & archived
Author Fred Templin
Last updated 2012-11-19 (Latest revision 2012-05-18)
RFC stream (None)
Formats
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:

Abstract

The 6rd tunnel MTU is currently recommended to be set to 1480. This is to avoid IPv4 fragmentation within the tunnel, but requires the 6rd tunnel ingress interface to drop any IPv6 packet larger than 1480 bytes and return an ICMPv6 Packet Too Big (PTB) message. Concerns for operational issues with both IPv4 and IPv6 Path MTU Discovery point to the possibility of MTU-related black holes when a packet is dropped due to an MTU restriction, so dropping packets is considered highly undesirable. Fortunately, the "Internet cell size" is 1500 bytes, i.e., the minimum MTU configured by the vast majority of links in the Internet. This document therefore presents a method to boost the 6rd MTU to 1500 bytes.

Authors

Fred Templin

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)