In message <[email protected]>, Hannes Frederic Sowa writes: > On 11/13/2012 02:34 AM, Fernando Gont wrote: > > * If IPV6_USE_MIN_MTU means "use an MTU of 1280 bytes" (as opposed to > > "use an MTU of *at most* 1280 bytes) then IPV6_USE_MIN_MTU might still > > result in fragmentation. If, OTOH, IPV6_USE_MIN_MTU means "use an MTU of > > at most 1280 bytes", then fragmentation might be prevented by signaling > > any received ICMPv6 PTB to the upper layer, such that the TCP SMSS is > > reduced acordngly, and hence fragmentation is avoided. > > Is the second case really possible? MSS is defined to be always derived > from the MTU. As the IPv6 minimum MTU is 1280 I see no way how the MSS > could sink below 1280-40-20 bytes.
While the MSS may be that, the segment size will change depending apon which TCP option are being sent. > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > [email protected] > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: [email protected] -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
