On Wed, 25 Sep 2002, Fred Baker wrote: > At 01:12 PM 9/25/2002 +0100, Lloyd Wood wrote: > >A datagram is self-describing; full source and destination. A fragment > >(IPv4 fragment) may not be. > > you sure? take a GOOD look at RFC 791... It is completely self-describing > in terms of getting itself there and where it belongs in the reassembled > datagram. If the other bits and pieces don't arrive, there is another > matter, but it is at that point a host issue, not a forwarding issue. I'm not sure that following fragments relying on a bit in another fragment saying 'following fragment' is truly self-describing. (Not having port nos in following fragments would only be a host issue if routers and firewalls never peeked at ports en route.) L. <http://www.ee.surrey.ac.uk/Personal/L.Wood/><L.Wood@ee.surrey.ac.uk>