Subject: Re: ping A->B != ping B->A ?
From: David Laight <firstname.lastname@example.org>
Date: 07/06/2004 18:38:41
On Tue, Jul 06, 2004 at 12:27:30PM +0200, Manuel Bouyer wrote:
> On Mon, Jul 05, 2004 at 09:36:25PM +0100, David Laight wrote:
> > > on B ping A:
> > > PING ianzag (192.168.100.37): 56 data bytes
> > > 64 bytes from 192.168.100.37: icmp_seq=0 ttl=255 time=2.444 ms
> > > 64 bytes from 192.168.100.37: icmp_seq=1 ttl=255 time=57.479 ms
> > > 64 bytes from 192.168.100.37: icmp_seq=2 ttl=255 time=44.911 ms
> > > 64 bytes from 192.168.100.37: icmp_seq=3 ttl=255 time=46.508 ms
> > > 64 bytes from 192.168.100.37: icmp_seq=4 ttl=255 time=0.004 ms
> > That looks rather like a reverse DNS issue.
> No, that would affect the time spent by ping to display the result,
> but not the RTT of the packet itself.
Except that a typical 'ping' program sends the requests from a signal
handler, and has the mainline processing the responses. Once the
first rDNS takes a long time the subsequent ping responses appear to
David Laight: email@example.com