A New Internet-Draft is available from the on-line Internet-Drafts directories. Title : Operational Issues with Tunnel Maximum Transmission Unit (MTU) Author(s) : Fred L. Templin Filename : draft-generic-v6ops-tunmtu-11.txt Pages : 7 Date : 2012-10-18 Abstract: The Maximum Transmission Unit (MTU) for popular IP-within-IP tunnels is currently recommended to be set to 1500 (or less) minus the length of the encapsulation headers when static MTU determination is used. This requires the tunnel ingress to either fragment any IP packet larger than the MTU or drop the packet and return an ICMP Packet Too Big (PTB) message. Concerns for operational issues with Path MTU Discovery (PMTUD) point to the possibility of MTU-related black holes when a packet is dropped due to an MTU restriction. The current "Internet cell size" is effectively 1500 bytes (i.e., the minimum MTU configured by the vast majority of links in the Internet) and should therefore also be the minimum MTU assigned to tunnels, but this has proven to be problematic in common operational practice. This document therefore discusses operational issues for IP-within-IP tunnel MTUs. The IETF datatracker status page for this draft is: https://datatracker.ietf.org/doc/draft-generic-v6ops-tunmtu There's also a htmlized version available at: http://tools.ietf.org/html/draft-generic-v6ops-tunmtu-11 A diff from the previous version is available at: http://www.ietf.org/rfcdiff?url2=draft-generic-v6ops-tunmtu-11 Internet-Drafts are also available by anonymous FTP at: ftp://ftp.ietf.org/internet-drafts/ _______________________________________________ I-D-Announce mailing list I-D-Announce@ietf.org https://www.ietf.org/mailman/listinfo/i-d-announce Internet-Draft directories: http://www.ietf.org/shadow.html or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
