[Gllug] ping behaviour

[Alain Williams]

I was waiting for a machine to boot, decided to ping it. I noticed that
the output was in bunches of 3 (ie seq: 1,2,3   5,6,7   9,10,11) with a
gap of several seconds between them.

OK: I know that ping sends out one ping/second. But why:

* do the host unreachables come out in groups of 3 ?
* to seq that are multiples of 4 get lost ?

This is running on Centos4 (aka RedHat E4), the machine in question would have been
reachable through a couple of D-Link switches.

Output below:

$ ping aragorn
PING aragorn.phcomp.co.uk (192.168.145.16) 56(84) bytes of data.
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=1 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=2 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=3 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=5 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=6 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=7 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=9 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=10 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=11 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=13 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=14 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=15 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=17 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=18 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=19 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=21 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=22 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=23 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=25 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=26 Destination Host Unreachable
>From mint.phcomp.co.uk (192.168.145.12) icmp_seq=27 Destination Host Unreachable

--- aragorn.phcomp.co.uk ping statistics ---
31 packets transmitted, 0 received, +21 errors, 100% packet loss, time 30000ms
, pipe 4

-- 
Alain Williams
Parliament Hill Computers Ltd.
Linux Consultant - Mail systems, Web sites, Networking, Programmer, IT Lecturer.
+44 (0) 787 668 0256  http://www.phcomp.co.uk/

#include <std_disclaimer.h>
-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug