Ping Reply example kernel

To: oskit-users@fast.cs.utah.edu
Subject: Ping Reply example kernel
From: Vishal Zinjuvadia <zvishal@ittc.ukans.edu>
Date: Mon, 10 Apr 2000 11:32:14 -0500
Sender: owner-oskit-users@fast.cs.utah.edu
Hi

         I had a problem with the pingreply example kernels. Following
is
         the outcome of a normal ping when we do a tcpdump

         11:16:34.057939 george.ittc.ukans.edu > spacely.ittc.ukans.edu:

          icmp: echo request
          11:16:34.058490 spacely.ittc.ukans.edu >
george.ittc.ukans.edu:
          icmp: echo reply


           Following is when we ping a machine (elory) booted with the
ping
           example  kernel. There seems to be no echo reply to the ping
request here.

           11:15:11.540025 george.ittc.ukans.edu > elroy.ittc.ukans.edu:

             icmp: echo request

            I also introduced permanent entries in the arp table for the
two machines - elroy and george.

        Could  some one help us figure out the problem here

Thanks

Vishal


On Sun, 2 Apr 2000, Alastair Reid wrote:

                 >
                 > A few easy things to try:
                 >
                 > Run tcpdump on all machines between the pinger and
the test
                 > machine.
                 > (You have to run on the routers themselves because on

                 > switched
                 > ethernet non-broadcast packets get filtered by the
hubs.)
                 > Check
                 > whether the echo request is getting to the test
machine and
                 > whether
                 > anything is being sent back.  (an incorrect checksum,
for
                 > example,
                 > will be discarded by ping).
                 >
                 > Run arp -a -n on the last machine in the host/router
chain
                 > that should
                 > be sending the packet to the test machine.  You
should see
                 > an arp
                 > entry for your test machine.  If it's "incomplete",
the
                 > problem is in
                 > the arp response code and you can temporarily work
round it
                 > (to test
                 > the rest of the system) by manually adding an arp
entry.
                 >
                 > --
                 > Alastair Reid        reid@cs.utah.edu
                 > http://www.cs.utah.edu/~reid/
                 >