Dns Management

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Revision as of 20:51, 27 September 2011 by Meshca (talk | contribs) (added to test section)

Introduction

A DNS server manages name resolution of computers on a subdomain. For example, going to docs.cslabs.clarkson.edu you are using clarkson.edu's DNS server to find the ip address of cslabs. This would be the CSLabs' DNS server. Now we use the CSLabs' DNS server to find the ip address of docs.

Where are the files?

The files you need to edit are in /var/named/ on DNS1. They link to corresponding files in /var/named/chroot/var/named/. You need to be root to edit these files.

What needs to be changed?

cslabs.clarkson.edu.zone

game            IN      A       128.153.145.36
tremulous       IN      CNAME   game

This snippet of the file shows that game.cslabs should be resolved 128.153.145.36. It then goes on to specify that tremulous.cslabs should resolve to the same address as game.cslabs.


145.153.128.in-addr.arpa

3       IN      PTR     dns1.cslabs.clarkson.edu.

How to push the changes to DNS2

Make sure that the serial# has been changed in any edited files. Then run rndc reload.

Testing

To check that your changes worked properly use the nslookup command. Lets say that you wanted to check game.cslabs. You would run:

root@dns1 ~]# nslookup game.cslabs 128.153.145.3
Server:		128.153.145.3
Address:	128.153.145.3#53

Name:	game.cslabs.clarkson.edu
Address: 128.153.145.36

root@dns1 ~]# nslookup game.cslabs 128.153.145.4
Server:		128.153.145.4
Address:	128.153.145.4#53

Name:	game.cslabs.clarkson.edu
Address: 128.153.145.36

This shows that both DNS1 and DNS2 resolve game.cslabs to 128.153.145.36 which is correct.