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check_http_fwb - nagios plugin for checking HTTP service


check_http_fwb -I ip-address -w warnlevel -c critlevel [ -p port ] [ -H http11_hostname ] [ -u remotefile ] [ -A user_agent ] [ -t timeout ] [ -G ] [ -D ]


check_http_fwb is a nagios plugin for checking HTTP. It differs from check_http by missing features which are rarely used, having a small codesize (7 KB statical code, diet-compiled and sstripped) and doing per default only a HEAD request.


-I ip-address
Specify the IP address of the remote server to check.

-w warnlevel
Specify the warning level.

-c critlevel
Specify the critical level.

-p port
Specify the port of the http server on the remote host.

-H http11_hostname
Specify the hostname for name-based virtual hosts.

-u remotefile
Instead of using the default "/" you can request a different file.

-A user_agent
Specify the HTTP user agent (default: "check_http_fwb/1 (nagios-fwb)").

-t timeout
The plugins internal timeout in seconds (default: 10).

Use "GET". "HEAD" is the default in check_http_fwb and "GET" is the default in standard nagios plugin check_http.

Use TCP_DEFER_ACCEPT (see tcp(7) ). This can speed up our http-communication by approx. 10 percent, but it breaks tcp-communication by RFC - like many others too. It can also cause trouble with loadbalancers like F5 which send "early" ACK packets to the server before ACK from client.

See Also


Here’s one example showing a GET-request for :

$ check_http_fwb -I -w 2 -c 4 -p 8080 -H -u /myfile.txt -G
HTTP CRITICAL: HTTP/1.0 404 Not Found - 0.016 second response time |time=0.016978s


Frank Bergmann,

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