2000-06-14-00:36:08 Marc Slemko:
b) If you're a webserver or something else providing service Out There to random users, just nail the MTU at 1500, which will work for any Ethernet/PPP/SLIP out there. And if you're load balancing to geographically disparate servers, then your users are probably Out There, with an MTU almost guaranteed to be 1500.
Except that, technically, you are not permitted to just blindly send segments of such size. Well, you can but systems in the middle don't have to handle them. No?
No? I thought traffic only failed to flow when PMTU discovery was attempted (dont-fragment bit set on first packet) but the needed ICMP to make it work was being blocked. If you don't even try to do PMTU, then people who have paths where middle links have MTUs smaller than the smallest of the two end-points' MTUs will just have to fragment. And as long as they're rare, that shouldn't be much problem, no? -Bennett