Nagios has not received an update from host1

[Pratapa]

Hi,

User is complaining that he is receiving so many Warning alerts.

Message is showing as follows in Nagios:

Nagios has not received an update from host1 for at least 10 minutes.

They are all passive checks.

How can this be resolved?

Please help me.

[Pratapa]

I logged into the client machine and executed the below command

/usr/local/nagios/bin/send_nsca -H nagiosserver -c /usr/local/nagios/etc/send_nsca.cfg -p 5667
Error: Timeout after 10 seconds

Client machine is AIX server.

[Pratapa]

From Nagios server I executed the following command.

[root@nagiosserver]# telnet clientmachine 5667
Trying xx.xx.xx.xx...
telnet: connect to address xx.xx.xx.xx: Connection refused

[lmiltchev]

Have you added the client's IP address to the "only_from" line in the "/etc/xinetd.d/nsca" file on your Nagios server? By default, NSCA can only allows connections from the Nagios server itself. In order to allow remote hosts and applications to send passive results to Nagios you will need to configure access. After adding the remote machine's IP address to "/etc/xinetd.d/nsca", you will need to restart xinetd, so that changes can take effect:

Code: Select all

service xinetd restart

Also, have you checked you firewall rules? Is TCP port 5667 open?

[Pratapa]

There are no files under /etc/xinetd.d

[root@nagiosserver xinetd.d]# pwd
/etc/xinetd.d
[root@nagiosserver xinetd.d]# ls
[root@nagiosserver xinetd.d]#



[root@nagiosserver]# ps -ef|grep nsca
nagios 16542 1 0 Sep06 ? 00:11:52 /opt/nagios/bin/nsca --single -c /opt/nagios/etc/nsca.cfg
root 87413 75750 0 17:19 pts/2 00:00:00 grep --color=auto nsca


[root@nagiosserver xinetd.d]# /bin/systemctl status xinetd.service
Unit xinetd.service could not be found.

Port 5667 is open on Nagios server.

[root@nagiosserver ]# netstat -an|grep 5667
tcp 129 0 0.0.0.0:5667 0.0.0.0:* LISTEN

output truncated....

[root@nagiosserver ]# netstat -an|grep 5667|wc -l
127


There are so many processes listening on port 5667. Some of them are in CLOSE_WAIT and some are in SYN_RECV

[Pratapa]

[root@nagiosserver]# lsof -i|grep 5667
nsca 16542 nagios 4u IPv4 13404327 0t0 TCP *:5667 (LISTEN)
nsca 16542 nagios 5u IPv4 1509107706 0t0 TCP nagiosserver:5667->server1.be.corp:51587 (CLOSE_WAIT)

[Pratapa]

This issue is resolved after killing the process having PID 16542.

Restarted nsca service.

[lmiltchev]

I am glad your issue has been resolved! I am closing this topic now. If you have any further questions/issues, please start a new thread.