This is the mail archive of the
ecos-discuss@sources.redhat.com
mailing list for the eCos project.
Re: can get DHCP IP address, but cannot ping
On Fri, Jan 14, 2005 at 08:08:24PM +0900, xxchen wrote:
> Hello, Nickolay
>
> >>
> >run "tcpdump icmp -n" and ping
> >
> >
>
> Thank you very much. I ran "tcpdump icmp -n" 2 times and then get the
> following result.
>
> (1)the first time:
> ------------------------------------------------
> message of host:
> ----------------------------------------------
> 19:50:23.759123 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:50:23.759297 192.168.0.59 > 192.168.0.198: icmp: echo reply
> 19:50:31.201261 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:50:31.201319 192.168.0.59 > 192.168.0.198: icmp: echo reply
> 19:50:38.572536 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:50:38.572619 192.168.0.59 > 192.168.0.198: icmp: echo reply
> 19:50:45.890345 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:50:45.890428 192.168.0.59 > 192.168.0.198: icmp: echo reply
> 19:51:00.333976 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:51:00.334057 192.168.0.59 > 192.168.0.198: icmp: echo reply
> 19:51:14.777603 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:51:14.777691 192.168.0.59 > 192.168.0.198: icmp: echo reply
> 19:51:29.221228 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:51:43.664851 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:51:58.108477 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:52:12.552102 192.168.0.198 > 192.168.0.59: icmp: echo request
>
> ----------------------------------------------------------
> while the target output following message:
> ------------------------------------------
> PING - received 3 of 10 expected.
>
>
> (2)the second time:
> ----------------------------------------------------
> message of host:
> --------------------------------------------------
> 19:54:37.019363 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:54:51.462989 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:55:05.906613 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:55:20.350239 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:55:34.793867 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:55:49.237488 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:56:03.681114 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:56:18.124738 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:56:32.568365 192.168.0.198 > 192.168.0.59: icmp: echo request
> 19:56:47.011988 192.168.0.198 > 192.168.0.59: icmp: echo request
>
> -------------------------------------------------------
> while the target output:
> ---------------------------------------------------
> PING - received 0 of 10 expected.
>
> the host has received request but why not send reply?
> Looking forward to your further advice.
My guess would be the arp entry has timed out. You host might be
arp'ing but the filter you used with tcpdump will not show it.
Andrew
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss