> From nanog-bounces+bonomi=mail.r-bonomi....@nanog.org Sat Sep 25 21:56:30 > 2010 > Date: Sat, 25 Sep 2010 21:57:53 -0500 > Subject: large icmp packet issue > From: fedora fedora <fedoraf...@gmail.com> > To: nanog@nanog.org > > I am having problem getting ping to work to a specific destination host when > using large size icmp packet and i am hoping someone here can offer some > suggestion. > > With regular ping, i can ping this remote host without any problem, but if i > crank up the packet size to above 1500 (1500 still works), i won't get any > icmp reply. > > My first thought was this was a pmtu issue. but when I ran tcpdump on this > remote host, i saw the incoming ping requests and this host actually sent > back icmp replies, so it appears that there is some device in between > blocking these large size icmp reply packets. > > Here is the question, how can i find out which hop on the path is causing > this behavior?
Did you consider doing a traceroute? And then pinging the intermediate machines? with the big packets, that is. you'll get a response from the 'near side' of the problem, but -not- from any machine on the far side of it. Ping with small packets first, to discovr machines that dont respond to pings at all.
