Hi all, I have this strange problem with my openbsd setup. I have a box which I use for one of my networks gateway. It has two NICs. One for internal network with ethernet connection (fxp0 driver) and one for external network (internet) with pppoe connection (rl0 driver). pppoe connection is set up using user land configuration. mtu on pppoe link is set to 1492. Everything works fine until I try to ping it with packet size of 1457 (from outside - internet). I run two parallel pings - one normal and one set to 1457 and DF bit set. When the second ping starts the connection to the box is disrupted the second ping shows "Request timed out" and the first ping shows "TTL expired in transit". And if I do the same experiment with the second ping packet size set to 1456, everything works fine. I don't understand why this is happening... The second ping shouldn't disrupt the first ping. Event if packet size is too big... It shouldn't influence the whole box's work... I've done this experiment on other boxes (with openbsd) and everything worked fine - if the second pings packet size was too big then it got answers "Packet needs to be fragmented but DF set" or "Request timed out", but the first ping worked fine (it always got good answers and not "TTL expired in transit"). I've tried to play with pf's scrub rule (max-mms 1492), but it didn't help. Can you help me?
