Nagios Support Forum

Hello everyone,

I am pretty new to Nagios, and I have a question about some of the output. There are a bunch of services that go down in Nagios that appear to be random. They usually only go down for no more than 20 or 30 seconds. When they do go down, this is the output that Nagios produces.



It says "CRITICAL - Bogus ICMP: Port Unreachable(IP Address of Host/Service)"

After a lot of google searching, I have no idea what this means. Can anyone help?

Thanks for your time.

That message in english is "Destination port unreachable" which means that the ICMP port is blocked on the host being pinged. Why this would happen periodically I have no idea... unless the firewall on your host is being turned on and off at random

jsmurphy wrote:That message in english is "Destination port unreachable" which means that the ICMP port is blocked on the host being pinged. Why this would happen periodically I have no idea... unless the firewall on your host is being turned on and off at random

Thanks! I actually just found some code to show that.

My question to you would be, is it possible these hosts have a sort of DoS prevention measure on them, so they would turn away too many ping requests?

They are card readers.