Name

tcp — check if the host does respond to tcp connection request

Synopsis

[ service=pop3,smtp,printer tcp service=ftp timeout=20 ]tcp

Probing well known services on non-default ports:

[server1 check=tcp service=ftp(21),smtp(3325)]tcp

Content awareness:

[ server1 check=tcp service=custom(80) send="HEAD / HTTP/1.0\r\n\r\n" expect="HTTP" ]tcp

Description

Some well known services (such as smtp, pop3, nntp, ica) will be recognized and not only connected to but also checked against some expect/send pairs (e.g. when checking SMTP uxmon will expect an answer starting with '22'). service is a variable set to a comma separated list of services 'tcp' should check. timeout is the maximum time the tcp check waits for a response (default: 8s).

Some well known services have their own aliases, so they can directly be listed without "service=... tcp", e.g.

 server1 pop3 smtp printer

is ok.

You can apply a test for a well known service to a non-default port by using the syntax service=service(port). Content awereness can be added. The semantics of above given example is: connect to port 80 of server1, send the string specified with the send argument, check if the stream server1 sends contains the regular expression specified with expect.