Default MSS for most linux is 0, which causes the kernel to calculate it as the interface MTU-40bytes. You can either change the MTU on the interface or more specifically use the 'ip route <ipblock> dev <interface> advmss <new mss>' command to update it on a per route basis.
~J -----Original Message----- From: Robert E. Seastrom [mailto:r...@seastrom.com] Sent: Thursday, April 30, 2009 7:12 AM To: Randy Bush Cc: nanog@nanog.org Subject: Re: Important New Requirement for IPv4 Requests Randy Bush <ra...@psg.com> writes: > mtu clue is also useful. here on tokyo b-flets, and i would guess in > many other ppoe environments, you need to tune or lose big-time. But not difficult to beneficially MiM: in pf: scrub in on gre0 max-mss 1400 scrub out on gre0 max-mss 1400 in cisco-land: ip tcp adjust-mss 1400 i'm sure the linux folks can offer up something similar... -r
