[smokeping-users] Failed ping

[G.W. Haywood]

Hi there,

On Mon, 28 Nov 2011, Eric Brander wrote:

> I've been using Smokeping for several years now but I just recently
> started having a problem pinging a remote site. There are 4 IP
> addresses at this site and I'm able to ping and fping them all from
> the command line. However Smokeping has trouble pinging one of them -
> and it's not always the same one. Sometimes it will change which one
> it can't reach after just restarting, but only after it's been running
> for a while.
>
> I'm running fping every 60 seconds, with 10 56-byte pings.
>
> Tcpdump shows the first one of those pings recieve a reply but then
> the rest never get a reply:
>
> 09:26:14.734203 IP smokeping.host > ping.destination: ICMP echo
> request, id 6357, seq 1, length 64
> 09:26:14.739165 IP ping.destination > smokeping.host: ICMP echo reply,
> id 6357, seq 1, length 64
> 09:26:18.971583 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 3, length 64
> 09:26:19.974047 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 7, length 64
> 09:26:20.976558 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 11, length 64
> 09:26:21.980735 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 15, length 64
> 09:26:22.982603 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 19, length 64
> 09:26:23.984398 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 23, length 64
> 09:26:24.987040 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 27, length 64
> 09:26:25.988577 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 31, length 64
> 09:26:26.990818 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 35, length 64
> 09:26:27.992735 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 39, length 64
> 09:26:28.996583 IP smokeping.host > ping.destination: ICMP echo
> request, id 6376, seq 43, length 64
>
> Any ideas?

At the moment you don't know

1. if the pings leave the sending box,
2. if they arrive at the recipient box,
3. if they are replied to by the recipient,

and if they are replied to, you don't know

4. if the replies reach the pinging box.

You need to narrow it down.  Start by putting some instrumentation in
the system.  Probably the first thing I'd do is run 'tcpdump' on all
the appropriate boxes.

--

73,
Ged.