Hi again, Steve. > With any potential MTU issue I always start with something like > "ping -vDs 1472 arenabg.com" from various hosts and routers. > As you vary the sizes you should receive either an echo-reply or a > packet-too-big (confirm with a packet sniffer). If you don't receive any > reply > you might have found why and where PathMTU is broken. >
I tried the ping test. Here are some results ------- pinging from the OpenBSD router ------- $ ping -vDs 1472 arenabg.com PING arenabg.com (82.101.72.23): 1472 data bytes 1480 bytes from 82.101.72.23: icmp_seq=0 ttl=57 time=15.371 ms ------- pinging from the OpenBSD router ------- $ ping -vDs 1473 arenabg.com PING arenabg.com (82.101.72.24): 1473 data bytes ping: sendto: Message too long ping: wrote arenabg.com 1501 chars, ret=-1 ------- pinging from a machine behind the router ------- $ ping -vds 1472 arenabg.com PING arenabg.com (82.101.72.24) 1472(1500) bytes of data. 1480 bytes from pleasure-dome.arenabg.com (82.101.72.24): icmp_seq=1 ttl=56 time=28.1 ms ------- pinging from a machine behind the router ------- $ ping -vds 1473 arenabg.com PING arenabg.com (82.101.72.23) 1473(1501) bytes of data. # no reply is recieved - 100% packet loss ------- pinging from a machine outside my network ------- $ ping -vDs 1472 arenabg.com PING arenabg.com (82.101.72.24): 1472 data bytes 1480 bytes from 82.101.72.24: icmp_seq=0 ttl=61 time=6.288 ms ------- pinging from a machine outside my network ------- $ ping -vDs 1473 arenabg.com PING arenabg.com (82.101.72.23): 1473 data bytes ping: sendto: Message too long The last results are from a machine that is not in my provider's network either. I'd be happy if you could post some comment on this. Does this mean that there is a PMTU problem with my OBSD router? Thanks, Alexander
