I have nagios setup as I want it, but last night it started alerting me of a problem pinging the internet. (I have a check that pings www.google.com to test that the internet is still working)
Now looking into this problem I can see that my network can ping the internet fine, the server that runs nagios can also ping the internet but if I run
./check_ping -H www.google.com -w -c
I get Network Unreachable
./check_ping -H [IP address of google] -w -c
I get ping OK
I can use ping on both ip and domain name and they both work fine.
Anyone got any clues as to where the problem lies, is it nagios or do I have a problem with DNS in my nagios box or in my network somewhere?