On 01 Aug 2013, at 18:40 , Templin, Fred L wrote: >> If the physical MTU is 1280, then the tunnel MTU will be smaller. > > Not allowed; the tunnel MUST be able to do a minimum 1280.
A number of nested tunnel deployments that I'm aware of simply do not support that 1280 MTU inside the innermost tunnel -- because of accumulated tunnel encapsulation overhead. Those nested tunnel deployments are just as real as the PMTUD operational issues. Each is applicable to some environments, but not necessarily to all paths and all deployments. If this document is to be reality-based, we need to acknowledge all of the operational realities that have an impact on this topic, not just acknowledge some of the operational realities. Yours, Ran -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
