check_http adding domain name to fqdn ?

An open discussion forum for obtaining help with Nagios Core. Nagios Core users of all experience levels are welcome here. Subforum have been created for the discussion of Nagios Core and Nagios Plugin development.

NOTE: The mailing lists have been deprecated in favor of this forum in order to expedite support and provide additional features not available on the old mailing list.

check_http adding domain name to fqdn ?

Postby jlom » Mon May 21, 2018 9:25 am


I have a weird problem I can't figure out why this would be happening.

I Have a site being checked with check_http every once in a while I am getting my domain added to the end of the FQDN.
[2018-05-21T08:17:10] SERVICE ALERT:;HTTP-Port80-slower-site;CRITICAL;SOFT;1;Temporary failure in name resolution

Here is the log from my DNS server which is how I know this is happening

2018-05-21T08:17:10-04:00 named[15326]: client ( query: IN AAAA + (
Posts: 17
Joined: Mon Dec 04, 2017 4:49 pm

Re: check_http adding domain name to fqdn ?

Postby mcapra » Tue May 22, 2018 8:45 am

Which version of check_http are you using? This should provide that information:

Code: Select all
/path/to/check_http --version

Which operating system and version of that operating system is doing the executing of check_http?

I'm pretty sure this is a general getaddrinfo failure that's happening here:

Which would indicate this is a DNS related problem, possibly NXDOMAIN hijacking from some malicious actor (there's not much to gain, frankly), competing resolvers, or some other misconfigured aspect of name resolution on the machine itself.

I'm not totally convinced this is a check_http specific problem, but we'll do our due diligence.
Former Nagios employee
User avatar
Posts: 3584
Joined: Thu May 05, 2016 3:54 pm

Re: check_http adding domain name to fqdn ?

Postby cdienger » Tue May 22, 2018 1:07 pm

+1 on a dns resolution issue. If a hostname cannot be resolved, it will try again but tack on the domain name found in /etc/resolv.conf.
As of May 25th, 2018, all communications with Nagios Enterprises and its employees are covered under our new Privacy Policy.
User avatar
Support Tech
Posts: 3686
Joined: Tue Feb 07, 2017 11:26 am

Return to Nagios Core

Who is online

Users browsing this forum: MSN [Bot] and 12 guests