That's all fine Valdis, but no one does MTU check on the internet or pmtu
checks. This is all LAN-based...
Umm.. I'm confused. What's all LAN-based?
Or you saying that PMTU Discovery isn't used *at all*?
Or that it's not *widely* used, mostly because a large chunk of the net *is*
stuck at 1500-byte MTUs, and a large fraction of the rest has broken PMTU
discovery because of boneheaded ICMP filtering?