Empty output from agent, execution time 0.0sec for Cent OS

[arun1727]

CRIT-Empty output from agent,execution time 0.0sec

Unable to fix the above mentioned alert for centOS server

[gormank]

You may want to make sure the relevant port is open on the remote host and if that doesn't help, do a web search on the message.
Is this on Check_MK?

[arun1727]

Our support team have opened the port but in Nagios server we are unable to get the telnet output

[r]# telnet X.X.X.X 6556
Trying X.X.X.X...
Connected to X.X.X.X.
Escape character is '^]'.
Connection closed by foreign host.

[arun1727]

yes its from Check_mk

[gormank]

The quickest way to get pointed in the right direction or to get ideas about an issue is to do a search of the internet.

https://www.google.com/search?biw=1102& ... CAw&uact=5

I guess the port isn't open somewhere along the way to the remote host or whatever agent is supposed to listen on 6556 isn't.

Note that in the link there's a forum specific to checkmk that mentions this issue.