nanog mailing list archives
IP tunnel MTU
From: "Templin, Fred L" <Fred.L.Templin () boeing com>
Date: Mon, 22 Oct 2012 15:24:24 -0700
Hello, Several months ago, there was discussion on the list regarding IP tunnel maximum transmission unit (MTU). Since that time, it has been brought to my attention by members of my company's network operations staff that tunnel MTU is a very real problem they need to cope with on a daily basis - especially with the growing need to depend on both tunnels and tunnels-within-tunnels to track mobile devices. Since tunnels always reduce the effective MTU seen by data packets due to the encapsulation overhead, the only two ways to accommodate the tunnel MTU is either through the use of path MTU discovery or through fragmentation and reassembly. Unfortunately, both are known to be problematic in a non-trivial number of cases. The discussions on NANOG from back in the June timeframe resulted in "Operational Issues with Tunnel Maximum transmission Unit": https://datatracker.ietf.org/doc/draft-generic-v6ops-tunmtu/ I would like to ask this group to now give this document a look and post your comments/thoughts/experiences. For example, has the tunnel MTU problem crept into daily operational considerations to the point that we should now at least be documenting it and preferably trying to do something about it? From talking to our staff, I believe the answer is yes but it would be good to have confirmation from others. Thanks in advance for your thoughts, Fred fred.l.templin () boeing com
Current thread:
- Re: Please, talk me down., (continued)
- Re: Please, talk me down. JP Viljoen (Oct 16)
- Re: Please, talk me down. John Levine (Oct 17)
- Re: Please, talk me down. Nicolai (Oct 17)
- Re: Please, talk me down. Jay Mitchell (Oct 21)
- Re: Please, talk me down. Jay Mitchell (Oct 21)
- Re: Please, talk me down. Nicolai (Oct 21)
- RE: Please, talk me down. Keith Medcalf (Oct 21)
- Re: Please, talk me down. Suresh Ramasubramanian (Oct 21)
- Re: Please, talk me down. Mark Andrews (Oct 21)
- forward and reverse DNS (was: Please, talk me down.) Andrew Sullivan (Oct 22)
- IP tunnel MTU Templin, Fred L (Oct 22)
- Re: IP tunnel MTU Dobbins, Roland (Oct 22)
- RE: IP tunnel MTU Templin, Fred L (Oct 23)
- Re: IP tunnel MTU Ray Soucy (Oct 29)
- RE: IP tunnel MTU Templin, Fred L (Oct 29)
- Re: IP tunnel MTU Ray Soucy (Oct 29)
- Re: IP tunnel MTU Shahab Vahabzadeh (Oct 29)
- Re: IP tunnel MTU William Herrin (Oct 29)
- RE: IP tunnel MTU Templin, Fred L (Oct 29)
- Re: IP tunnel MTU Chris Woodfield (Oct 29)
- RE: IP tunnel MTU Templin, Fred L (Oct 30)