DNS IP address

[Jason Berendsen]

I have the situation where we have our DNS servers both primary and secondary running on 2 Red Hat 6 servers. I want to move this functionality to our HP-UX 11.00 servers, because they are upgraded and patched on a regular basis. I run into a problem with the fact that I want to run DNS on 2 of our production servers that are very rarely brought down. I am not able to change the IP addresses of these production servers, and I am not wanting to change the IP addresses of the DNS servers due to the large amount of servers with this IP address hard coded. The only way I can think to have my cake and eat it too is to put DNS in a Service Guard cluster. I know due to the redundancy of the secondary DNS server the ServiceGuard environment will afford me no more security. But it would allow the production servers to keep their IP addresses and allow me to use the current IP addresses of the DNS servers.

Questions:
Is there a better way to accomplish my goal?
Is anyone else running DNS in a ServiceGuard environment, if so how is it working?

Thanks in advance,

Jason

[James A. Donovan · Accepted solution]

Given your goal, the only way I can see to accomplish it would be to setup VLAN's on your HP server's NIC cards.

Take a look at the documentation, and see if you want to go down that road...

http://docs.hp.com/hpux/onlinedocs/T1453-90001/T1453-90001.html

[Mark Greene_1]

You could just move DNS to the HP's and go with those addressess. Pushing the change out to your desktops should be trivial. Both Microsoft and Novell have utilities for doing this (I don't know but would expect Apple to have something as well, if that applies). The hard part will be your other Unix systems which you will have to update individually or write a script using Expect to do it in the background. The amount of time involved shouldn't be any greater than the amount of time needed to setup a Service Guard cluster.

On the other hand, why not update the Red Hat boxes to 7.3 or 9? (Don't bother with 8.) You can schedule rpm updates daily, and the system will patch itself automatically--doesn't even require a reboot! All you'll have to do is review the logs to ensure all is going well.
Annual support will run you a whole $60.00 per server.

HTH
mark

[Bill Douglass]

You can add multiple ip address to the same physical LAN card, using IP index numbers (e.q. lan0 is 192.168.0.2, while lan0:1 192.168.0.25). Check out the ifconfig man page.

You should be able to do this without rebooting or bringing the original interface down.

[Steven E. Protter]

I think your goal is a good one and it sure beats the way many shops do it, running the DNS on a Microsoft(Can you see the blue screen of death) boxes.

As far as service guard goes, thats probably overkill, but its reliable. My HP-9000 DNS server hasn't been down in prime time for three years.

That being said, you set up the DNS on the HP-9000 server any way you want.

Migrate the DNS databases and test the heck out of it.

Then for the Linux boxes, change their resolv.conf files to poinit to the HP Cluster.

Then have any Microsoft clients that point to the Red Hat Servers change their DNS network information to the HP boxes.

We are not running Service Guard here, but we are running DNS on our production box to provide legacy compatibility to our old domain name.

SEP

[Kevin Wright]

upgrading your Redhat boxes is probably the best way to do this. Or setup some new boxes, either Redhat or Sun, then when you do a cutover, change the IP to your current DNS servers.

If youf DNS setup is designed correctly, there is no reason to have DNS in a cluster. Paying to put DNS in a Serviceguard cluster would be overkill to say the least.

[Rainer von Bongartz]

Not really a problem here.

You could add a second IP-Address to your HP servers which matches the configured IP addresses of your DNS servers.

ifconfig lanX:1 A.B.C.D

Now configure ans start DNS using
lanX:1

Regards
Rainer