I concur with Fred that IPv6 links over the network should have an MTU >1280 if possible.
The fragmentation that could occur at say the head-end of a tunnel seems enough of a contraindication in general for it having a 1280 MTU. Efficient use of (up)links is clearly another consideration when setting MTU (and MSS for that matter). Tim Enos Ps 127:3-5 -----Original Message----- From: Templin, Fred L <fred.l.temp...@boeing.com> Sent: Friday, April 22, 2011 1:17 PM To: Bob Hinden <bob.hin...@gmail.com>; Dan Wing <dw...@cisco.com> Cc: ipv6@ietf.org <ipv6@ietf.org>; 'Brian E Carpenter' <brian.e.carpen...@gmail.com> Subject: RE: PMTU blackhole detection IMHO, IPv6 links that occur in the network (even tunnels) should try to do better than 1280 if possible. Otherwise, VPNs/tunnels that ride over the links may see a too-small MTU resulting in IPv6 fragmentation. Granted, doing better than 1280 may be difficult for some links. Thanks - Fred fred.l.temp...@boeing.com > -----Original Message----- > From: ipv6-boun...@ietf.org [mailto:ipv6-boun...@ietf.org] On > Behalf Of Bob Hinden > Sent: Wednesday, April 20, 2011 2:26 PM > To: Dan Wing > Cc: ipv6@ietf.org; Bob Hinden; 'Brian E Carpenter' > Subject: Re: PMTU blackhole detection > > Dan, > > > Ben Stasiewicz has done some research on IPv6 MTU problems, > > > http://ripe60.ripe.net/presentations/Stasiewicz-Measurements_o > f_IPv6_Path_MTU_Discovery_Behaviour.pdf > > > > Very interesting. A good next step would be to figure out > what caused each type of failure. > > Bob > > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
