Nagios returning OK with check_http and status 303

Question

Probably an easy question but search is not helping.

# ../libexec/check_http -H google.co.uk

Provides:

HTTP OK: HTTP/1.1 301 Moved Permanently - 592 bytes in 0.153 second response time|time=0.152933s;;;0.000000 size=592B;;;0

But

# ../libexec/check_http -H google.co.uk.thisisnotarealurl

Provides:

HTTP OK: HTTP/1.0 303 See Other - 212 bytes in 0.161 second response time|time=0.161133s;;;0.000000 size=212B;;;0

How can it be showing HTTP OK when the site doesn't exist?

Nagios is showing the site is OK whether it exists or not, is this normal?

Answer 1

Status 303 means the site is present, just somewhere else. Same for 301 (with different semantics). Thats not a Failure so yeah thats normal.

The question is why you get 303 for google.co.uk.thisisnotarealurl. Maybe some setup in your network (DNS proxy that always delivers some result? See also the comment of James_pic!)

What do you get if you hit that into a browser (from the same machine & setup of Nagios)