DNS related problem

[soia]

I have an interesting situation. I am currently on a workgroup model network. When i check my email under the workgroup model i have no problems whatsoever. I am also designing an Active Directory network Now when i setup an email account there and enter my POP3 and SMTP servers it says it doesn't find them. I have to enter the actual ip address of my email server to get my emails. What i dont get is why is it that on my workgroup model ill enter my POP3 and SMTP servers as names and on the Active Directory i have to enter the ip address.
Also i have no problem accessing the internet which makes it more mysterious. I know names are getting resolved but for some reason my mx records are not.

-SOIA

[Sgt_B]

Are both networks accessing the same DNS server for resolution?

[soia]

No they aren't. In the active directory there is an internal DNS server setup with forwarders to the external DNS servers, which are the same as the others.

[t2k2]

For access to the internet, you would be pointing to a different DNS server, wouldn't you? Could it be that your internal DNS server (for Active Directory) is configured improperly? This would explain why internal names are not being resolved. For your internet connection, you will be pointing to a DNS server that your ISP is probably managing. I need a little more information to see if I can help.

[Sgt_B]

From a client machine on the AD network do an nslookup on the internal DNS server. Try to query the pop3 and smtp addresses. Do they come back with a response? Can you resolve other internet names this way? If not, then you may need to open up the firewall to allow the internal dns server to query the external dns server (assuming there is a firewall).
From the sound of it, its doesnt seem like your internal dns server is forwarding correctly.

Either way, run the queries and let me know the response.

ps - Is there a firewall involved? Is there a proxy server involved? If you designate the external dns server on one of your client machines, can you then access the pop and smtp by name?

[soia]

How i set this up is as follows. When i created my internal dns i added a forwarder to go to the external dns servers, two from my isp and one of my own, to resolve the outside names. Now i can resolve all names except for mx records. I decided to remove my dns server from the list of forwarders. I can still resolve names but i cant resolve this mx record.

[Sgt_B]

If you have your clients go straight to one of the ISP dns servers, can you resolve he mx records then?

[soia]

When i did an nslookup on the dns server name i got this message
DNS request timed out
timeout 2 seconds
cant find server name for address xxx.xxx.xxx.xxx
default server unavailable
server: unknown
address: xxx.xxx.xxx.xxx

name: name does show up of internal dns server
address: xxx.xxx.xxx.xxx

alright now im totally confused. I took out my external dns from the list of forwarders and just used my isp's external dns servers. now i cant resolve any internet names?????

Im confused now

[Sgt_B]

That sounds like your internal dns server cannot reach the IPS's dns servers, but can reach your external dns server. Do you have the mx records defined on your external dns server? If you do not, then this would explain your problem. For some reason your AD network cannot reach your ISP's dns servers, or they cannot send dns queries to those servers.

Is there a firewall involved in this?

[soia]

no firewall is involved in this at the moment. it set up on a test network that bypasses the firewall. What i dont get is if i can resolve names on the internet, why cant i see the mx records???? wouldnt the dns server get the mx record from the appropriate dns server