On Mon, Jun 9, 2008 at 9:06 AM, B A <[EMAIL PROTECTED]> wrote: > bash-3.2# pfctl -sr > scrub all no-df random-id max-mss 1400 fragment reassemble > pass in quick all flags S/SA keep state > pass out quick all flags S/SA keep state
> Ok. Here is openbsd tcpdump. But I still see len 1440 packets. > > 03:57:54.035986 192.168.133.200.9901 > 192.168.133.1.80: S [tcp sum ok] > 1790495358:1790495358(0) win 16384 <mss 1400,nop,nop,sackOK,nop,wscale > 0,nop,nop,timestamp 3743718606 0> (ttl 64, id 55493, len 64) > 03:57:54.036047 192.168.133.1.80 > 192.168.133.200.9901: S [tcp sum ok] > 2480387518:2480387518(0) ack 1790495359 win 5792 <mss 1460,sackOK,timestamp > 343617 3743718606,nop,wscale 7> (DF) (ttl 64, id 0, len 60) > 03:57:54.036080 192.168.133.200.9901 > 192.168.133.1.80: . [tcp sum ok] ack 1 > win 16384 <nop,nop,timestamp 3743718606 343617> (ttl 64, id 40579, len 52) > 03:57:54.036210 192.168.133.200.9901 > 192.168.133.1.80: P 1:70(69) ack 1 win > 16384 <nop,nop,timestamp 3743718606 343617> (ttl 64, id 7424, len 121) > 03:57:54.036257 192.168.133.1.80 > 192.168.133.200.9901: . [tcp sum ok] ack > 70 win 46 <nop,nop,timestamp 343617 3743718606> (DF) (ttl 64, id 35838, len > 52) > 03:57:54.040971 192.168.133.1.80 > 192.168.133.200.9901: P 1:229(228) ack 70 > win 46 <nop,nop,timestamp 343617 3743718606> (DF) (ttl 64, id 35839, len 280) > 03:57:54.040976 192.168.133.1.80 > 192.168.133.200.9901: . 229:1617(1388) ack > 70 win 46 <nop,nop,timestamp 343617 3743718606> (DF) (ttl 64, id 35840, len > 1440) > 03:57:54.040979 192.168.133.1.80 > 192.168.133.200.9901: . 1617:3005(1388) > ack 70 win 46 <nop,nop,timestamp 343617 3743718606> (DF) (ttl 64, id 35841, > len 1440) You might want to read up on packet structures as this is working as expected. The header of a TCP packet is normally 40 bytes--so you're seeing a maximum MSS of 1400 bytes and an MTU of 1440 bytes.
