On Tue, 11 May 2004 13:44:16 +0900 Masataka Ohta <mohta@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Mark Smith; > > > I'm keen to > > find out if my understanding of PMTUD purpose and operation > > is incorrect. > > Read the RFC or my quotation of it. > Ok, well, I haven't got far into it, and it seems to correspond to what I've understood : "2. Protocol overview In this memo, we describe a technique for using the Don't Fragment (DF) bit in the IP header to dynamically discover the PMTU of a path. The basic idea is that a source host initially assumes that the PMTU of a path is the (known) MTU of its first hop, and sends all datagrams on that path with the DF bit set. If any of the datagrams are too large to be forwarded without fragmentation by some router along the path, that router will discard them and return ICMP Destination Unreachable messages with a code meaning "fragmentation needed and DF set" [7]. Upon receipt of such a message (henceforth called a "Datagram Too Big" message), the source host reduces its assumed PMTU for the path." I'll continue reading, although I'm happy enough that my original understanding was correct. Regards, Mark. _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf
