What do you mean troubleshooting using telnet?
Do you mean you are using telnet to connect to another machine, or you are trying to connect using telnet to your DNS daemon?
Most DNS traffic is UDP not TCP, so trying to telnet to the DNS port will not work (used for transfers not lookups).
The best way to test DNS resolution is using the dig command.
man dig will give you the syntax, but here are a few pointers.
To view an A record entry
Code:
dig a www.mydomain.com
To do this against a specific DNS server
Code:
dig a www.mydomain.com @mydnsserver.mydomain.com
If this doesn't help try putting more details in your explanation, as it's hard to see what you are saying the problem is.