On Tue, 13 Jun 2000 23:50:55 EDT, "Steven M. Bellovin" said:
There are two places where it's very important. First, some server farms are on FDDI rings, so they have a higher MTU. Second -- and this
Yes, but I think I covered that in (a) - if you know there's a bigger MTU, nail it down. I dread to think of a load-balancer in the middle of a FDDI ring in a server farm ;)
one is growing in importance -- tunnels, for IPsec, PPTP, etc. -- generally have smaller MTUs. This very reply will travel over a tunnel with an MTU of, I believe, 1480.
Good point. It's been a long day, I wasn't QUITE thinking straight. Another respondent commented that Windows98 apparently nails an MTU of 576 on a dialup - Apparently I've not run into any Windows98 people setting their clocks off the server I got the numbers from. Also, he said that ADSL uses just under 1500. I don't have a Win98 or ADSL handy to check. ;) In any case, it's good fodder for an operational debate. ;) Valdis Kletnieks Operating Systems Analyst Virginia Tech