> > Oh nevermind, it affect the TCP option negotiation, so it causes the client > to send smaller packets. So it is a general solution for TCP (and only > TCP). For UDP, the mtu still needs to be reduced at the client.
All but linux however do the right thing on UDP and don't send it with DF sent, which means it should be refragmented if it goes through a bottleneck. (Of course, ~10% of the systems on the Internet can't process UDP fragments, but thats orthoginal (usually) to the PMTU problems)
