Nagios Support Forum

We are currently migrating our old Nagios core server to a new host. From what I've seen so far, I don't need to change the client software on any of the hosts we communicate with (we are also upgrading the core to latest release and changing the O/S from Solaris to Ubuntu.

All well and good. My problem is with the allowed_hosts parameter in nrpe.cfg in the clients. As it currently has an IP in it, and we are moving the core, I'm having to visit all the monitored boxes to add the new address in. I was thinking that I don't want to do this again if I can avoid it, and use a DNS entry instead. That way, any future migratoins can be managed by a change of DNS.

Got a name allocated, and the Solaris boxes are fine. The Windows boxes refuse connection. I check that the host can resolve the name, and it can. Restart the service, and it still refuses to connect where I use a DNS entry in allowed_hosts.

Any ideas?

Thanks.

I'm assuming nsclient++?

I found this:

BEWARE: NSClient++ will not resolve the IP address of DNS entries if the service is set to startup automatically. Use an IP address instead or set cache_allowed_hosts=0 see above.

here:

http://www.nsclient.org/nscp/wiki/NSCli ... figuration

We aren't using that, but the standard Nrpe client listening on 5666. Don't know why they were set up initially like that, but they are, and they work, but just not woth DNS names. Hope this makes sense. I'm not a Windows admin.

The confusion here stems from what you stated above:

The Windows boxes refuse connection. I check that the host can resolve the name, and it can. Restart the service, and it still refuses to connect where I use a DNS entry in allowed_hosts.

Windows boxes normally use NSClient++ as their NRPE client. Is that what they are using?

No they are not. I'll look in to that though. These were built initially by someone else, got connectivity, and found a working method and stuck with it. Now maybe that's not giving us the portability we are looking for. Thanks, I'll see what this client can do.

The only other option that I know of is nrpe_nt - which hasn't been maintained in nearly a decade

http://sourceforge.net/projects/nrpent/ ... rce=navbar

Ah ha! Looking at the docs that the guy who installed it left, it does look like it is using the old plugin. I'll look to see if I can get this upgraded and get it to work with DNS.

Thanks all for your help. It's much appreciated.

Shall we close this thread or leave it open while you test?