Unable to resolve HTTP Address

[cmpwat]

Hi all.

 

I have a bit of an issue with DNS, over the summer it decided to delete all its records (it might have had something to do with me, I couldn;t possible say either way!!!). Since then, it looks like all the Servers have a DNS record back in the DNS Sevrers however, when we try to go to a intranet site, like http://sv-app01, we get a DNS error where the address cannot be resolved?

 

Any ideas on what I need to put into DNS? I have a static entry to the IP Address in the forward lookup zone and a entry in the reverse lookup zone..... but really at a loss now?

[psydii]

Can you ping your DNS Servers from the clients?

 

Are your clients configured to use your internal DNS servers for lookups?

 

Are your clients have any other DNS servers configured for lookups? <-this would be bad.

 

From your DNS server check that it is pointing to itself or a replica for its primary DNS in TCP/IP properties... then check whether it can resolve the hosts by using their internal FQDN. You need to use the fqdn because otherwise it may fall back to netbios name resolution, which would give you a false positive.

 

If that works, check that your clients have the primary domain suffix configured via DHCP Scope Properties to be that of your internal domain.

[cmpwat]

Hi psydii

 

Thanks for you reply, I have added some responses below, but to be honest my knowledge of DNS is very flakey and have not had too much dealings with it in the past.

 

 

Can you ping your DNS Servers from the clients? - Yes, we can ping the Ip and DNS names of the servers.

 

Are your clients configured to use your internal DNS servers for lookups? - I am assuming you mean under the TCP settings?

 

Are your clients have any other DNS servers configured for lookups? <-this would be bad. - There are only 2 DNS Servers on the network.

 

From your DNS server check that it is pointing to itself or a replica for its primary DNS in TCP/IP properties... then check whether it can resolve the hosts by using their internal FQDN. You need to use the fqdn because otherwise it may fall back to netbios name resolution, which would give you a false positive. - ummmmm how?

 

If that works, check that your clients have the primary domain suffix configured via DHCP Scope Properties to be that of your internal domain. - We have option 015 DNS Domain Name switched on in DHCP.

[psydii]

Are your clients configured to use your internal DNS servers for lookups? - I am assuming you mean under the TCP settings?

Yes.

 

 

Are your clients have any other DNS servers configured for lookups? <-this would be bad. - There are only 2 DNS Servers on the network.

 

Sorry poor grammar there, it was an extension of the previous question. Let me rework it into something that makes sense: Confirm that your clients are configured to only use your DNS servers, and NOT any external DNS servers.

 

From your DNS server check that it is pointing to itself or a replica for its primary DNS in TCP/IP properties... then check whether it can resolve the hosts by using their internal FQDN. You need to use the fqdn because otherwise it may fall back to netbios name resolution, which would give you a false positive. - ummmmm how?[/QUOTE]

 

Exactly as you would on a client. Once you have confirmed that under TCP/IP settings it is using either itself or its partner, issue the following from a cmd window on your primary DNS server:

nslookup hostname.my.domain

where hostname is a server and my.domain is the internal DNS domain name of your AD.

 

 

Finally we may be barking up the wrong tree anyway.

Do you have an internal proxy server?

Do you have an external proxy server?

What entries apply to your client machines regarding proxy servers?

[cmpwat]

Sorry... as I said, trying to get up to speed asap!

 

All clients are set to use the 2 internal DNS servers. I have run the nslookup and get the following:

 

 

We do have an external proxy and an internal web filter, but the clients are all set to bypass the proxy when going to and domain.name address.