Recently we change the Nagios host to another IP address and found ourselves having to change a few dozen NSClient.ini files on the server. Even though we use DNS names as monitoring host (only nsclient access on port 12489/tcp is allowed from a certain host), NSClient by default caches the IP address (Using cache_allowed_hosts, which is set to “1″ by default) so we were bound to change quite some files.

To do this, we have to do the following:

• stop the nsclient service
• overwrite the nsclient.ini file
• start the nsclient service

For reasons i cannot disclose, this could not be done using any group policies. So we went the ghetto batch way:


@psexec \\%1 "C:\Program Files\NSClient++\NSclient++.exe" -uninstall
@xcopy /Y C:\tool\nagios\nsclient\* "\\%1\c$\program files\nsclient++\"
@psexec \\%1 "C:\Program Files\NSClient++\NSclient++.exe" -install
@psexec \\%1 "C:\Program Files\NSClient++\NSclient++.exe" -start
@echo Finished %1


This assumes you have nsclient++ already, which is an awesome piece of software that you can grab from nsclient.org, and that you have psexec installed to execute commands.

Using this script, you can just run C:\tool\nagios\update_nsc.bat server_name to have the server monitored again.

Thank you,
Michael

While we are breaking our heads on how this happens, we made a small two-liner script to enable a Windows service over the command line. We’ve put this in the recovery tab, and scheduled it as a task to run every hour.

The code to enable the DNS service, and to restart the service is below:


sc config DNS start= auto
net start dns


I know it’s very ghetto way of keeping DNS running, but we’re figuring out why DNS always shuts down. Until then, this provides us necesarry DNS uptime

Thanks,
Michael