Thanks, the thing is How can i be sure even if a device blocks my ping , it might have policy blocking ping at it at all.
On Sat, Sep 25, 2010 at 10:18 PM, Robert Bonomi <[email protected]>wrote: > > From [email protected] Sat Sep 25 > 21:56:30 2010 > > Date: Sat, 25 Sep 2010 21:57:53 -0500 > > Subject: large icmp packet issue > > From: fedora fedora <[email protected]> > > To: [email protected] > > > > 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. > >
