Watchdog sees self-generated ICMP packets as good ping results

[A. Karl Kornel]

Binary package hint: watchdog

I just installed the 'watchdog' package to monitor & shutdown my system if any one of the following takes place:

a) No traffic comes in on eth0
b) 10.1.16.85 (the machine's IP) doesn't respond to pings
c) 10.1.16.1 (the subnet's router) doesn't respond to pings

To test it, I modified the init script, changing $watchdog_options from "" (empty string) to "-q -v", so I can watch /var/log/syslog to see what's going on. Every 15 seconds, I get the messages "device eth0 received **** bytes", "got answer from target 10.1.16.85", and "got answer from 10.1.16.1"; everything looked OK.

The actual test came when I unplugged the network cable and waited. The first message changed to "device eth0 did not receive anything since last check", which I expected. However, watchdog continued to say "got answer from target {10.1.16.85, 10.1.16.1}", even though the network cable was disconnected.

Anyway, I tried pinging both 10.1.16.85 and 10.1.16.1. 10.1.16.85 responded to pings, but 10.1.16.1 kept on coming back with the ICMP message "Destination Host Unreachable". I had expected watchdog to differentiate between an ICMP error and an actual ping.

Another piece of interesting information: In watchdog.conf, I had three lines:

ping = 10.1.16.85
ping = 10.1.16.1
interface = eth0

When I commented out the first line, and restarted watchdog, it started to recognize the host unreachable message as what it was; when I removed the '-q' from the watchdog options, and restarted watchdog, the system was restarted (as expected).

[Daniel T Chen (crimsun)]

Is this symptom still reproducible in 8.10 alpha?

[Pedro Villavicencio (pedro)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to New. Thanks again!.