"Matt Sommer" writes: > Does RFC-879 still have any validity? > > " HOSTS MUST NOT SEND DATAGRAMS LARGER THAN 576 OCTETS UNLESS THEY > HAVE SPECIFIC KNOWLEDGE THAT THE DESTINATION HOST IS PREPARED TO > ACCEPT LARGER DATAGRAMS. No, that rule is no longer valid qua valid, in so far as negotiation and Path MTU discovery make it obsolete. Perry