On 2009-04-16 08:39, [email protected] wrote: > The benefits and tradeoffs are different for IPv6, which discards > header checksums, making the pseudo-header check more important for > reliability reasons.
That's unclear to me. One of the arguments for dropping the layer 3 checksum in IPv6 is that modern layer 2 solutions come with error detection. Making the layer 4 checksum compulsory strengthened that argument, of course. But I don't remember discussion of why the pseudo-header checksum is essential. In fact, when the IPNG WG was chartered in 11/94, the charter said: TCP/UDP: The IPng Working Group will specify the procedures for hosts to compute and verify TCP/UDP pseudo-headers. Any other changes to TCP beyond making TCP work with IPng are out of scope of the working group and should be dealt with by a TCPng Working Group. So it was taken for granted that we needed it. > > Besides, shouldn't NAT be difficult? Well, no. I don't like NAT because it damages end to end connectivity. If we fix things so that NAT doesn't damage connectivity, NAT ceases to be a problem. Abolishing the address component of the pseudo-header checksum would reduce the damage done by NAT. So in that sense, it would be a move in the right direction. Brian _______________________________________________ rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg
