topic Re: DNS configuration question in Operating System - HP-UX

DNS configuration question

Mauro Livi — Mon, 27 Dec 2010 21:32:20 GMT

Hi all,
We are changing DNS servers this weekend (basically one server is being shut down and another server will be used). The new server is already in operation and I've made the necessary changes to /etc/resolve.conf and /etc/hosts to reflect the new IP (i.e. added new server entries and commented out the old server entries)

As far as I can tell my HPUX servers are now using the new DNS server for name resolution and I've verified that by doing nslookup so that the result is:

Name Server: new DNS server name
Address: new DNS IP

Everything is exactly as mentioned above and to my knowledge that's the extent of what needs to be done. Just want to make sure I'm not missing anything.

Thanks
Mauro

Re: DNS configuration question

James R. Ferguson — Mon, 27 Dec 2010 21:40:18 GMT

Hi Mauro:

It appears that all is in order from your description.

Regards!

...JRF...

Re: DNS configuration question

Mauro Livi — Mon, 27 Dec 2010 21:42:15 GMT

Thanks JRF...thought so, just wanted to confirm.

Re: DNS configuration question

Bill Hassell — Mon, 27 Dec 2010 23:20:04 GMT

You may also want to use nsquery as it is more informative:

nsquery hosts abc.com
or
nsquery hosts 1.2.3.4

Always make sure that your nsswitch.conf exists and correctly specifies the order to resolve addresses.

Re: DNS configuration question

Mauro Livi — Mon, 27 Dec 2010 23:25:42 GMT

Good point Bill. Did nsquery and was also able to correctly resolve the name. I do have nsswitch.conf set up...in fact, in one server it looks at hosts first and on another looks at DNS first. In both cases, it was able to resolve.

Many thanks.
Mauro

Re: DNS configuration question

Bill Hassell — Tue, 28 Dec 2010 00:47:23 GMT

Just a recommendation: Always use hosts first. Not only is it much faster but you can bypass any updating delays (usually caused by other tasks that are more important). By putting the most important addresses (local servers) in /etc/hosts, DNS failures will not cause serious delays in your servers. And many backup programs (Data Protector for example) will query hostnames once for *EVERY* file that is backed up -- a very bad, but also very common, design flaw.