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Slow DNS resolution of internet websites

Hello All,

I have a bit of an issue with DNS and I am about to add a second domain controller and want to get this worked out ahead of time.  I will first explain the issue, and then give you as much detail as possible.

Currently there is 1 windows 2003 domain controller in this small network (25 users total) I have added the second server that will become the additional domain controller but at this point it is just a member server on the domain, no AD roles active on it.

My clients on the network, and DC included are experiencing slow internet access.  I test it and it is a  clear pause from when you make a request, it pauses, then after several seconds it comes down very fast.

I have thought it is a DNS issue, so on the member server I added, I had it get it's address through DHCP and it received the following (some blocked out for security purposes)

Windows IP Configuration



   Host Name . . . . . . . . . . . . : AddServer-02
   Primary Dns Suffix  . . . . . . . : xxxxxxxx.local
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : xxxxxxxx.local

Ethernet adapter Local Area Connection:
   Connection-specific DNS Suffix  . : xxxxxxxx.local
   Description . . . . . . . . . . . : Broadcom BCM5708C NetXtreme II GigE (NDIS VBD Client)
   Physical Address. . . . . . . . . : 00-15-C5-E8-4E-15
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IP Address. . . . . . . . . . . . : 192.168.1.187
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.3
   DNS Servers . . . . . . . . . . . : 192.168.1.3  (these are the current DC's addresses)
                                              192.168.1.4
   Primary WINS Server . . . . . . . : 192.168.1.3
   Lease Obtained. . . . . . . . . . : Monday, October 30, 2006 10:03:17 AM
   Lease Expires . . . . . . . . . . : Sunday, January 28, 2007 10:03:17 AM


When I have that website come up very slow, now if I just take the DNS server part and disable the DHCP for it and set it to:
207.173.224.3
206.13.31.12

Which are our ISP dns servers then everything is great, very fast, instant, as it should be.

My quesiton is should these addresses be configured somewhere in the existing DNS in Active Directory?  It seems like it looks all around locally for the site, then queries root hint servers, or something else?   I need to figure out when the resolution of external site is so sloooww  for the current AD environment.

Thanks

Bill
0
CRNorthAmerica
Asked:
CRNorthAmerica
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1 Solution
 
Chris GralikeSpecialistCommented:
Do you use dns forwarding on your DNS server? or do you rely on the root hints, and is cashing enabled?
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CRNorthAmericaAuthor Commented:
Where in the DNS information do I look for forwarding?  I know if you don't have forwarding then it automatically looks at root hints.  Yes, caching is enabled.
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CRNorthAmericaAuthor Commented:
yes forwarders are turned on for "all other dns domains" and it is set to the dns servers that I showed above
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Chris GralikeSpecialistCommented:
The forwarder should actually point toward an internet dns server.

All zones ie; .google.com. (forward lookup)
All IP addresses not part of your network (in-addr-arpa)
are forwarded to the dns server(s) in the forwarding list...

Use the dns server of your internet provider as the forwarding address

regards,
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Chris GralikeSpecialistCommented:
All zones ie; .google.com. (forward lookup) not part of your domain zone (mydomain.local)

typo ;)
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CRNorthAmericaAuthor Commented:
That is what I have -

In DNS Domain: (of the forwarders tab)
All Other DNS domains

and they forward to the IP's of the DNS server from the ISP
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CRNorthAmericaAuthor Commented:
looks like there was a typo in the forwarders that a previous person had in there. Thanks Buddy!
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Chris GralikeSpecialistCommented:
okey try this,

go to the command prompt of any client,

Start > Execute > cmd.exe [enter]

ipconfig /flushdns [enter]   (dont do this on a server! but a client)

nslookup [enter]
>set debug [enter]
>server (inet dns ip or name) [enter]
>google.com [enter]

and see what happens in the query ;) and post that info if it doesnt make sense :D

Regards,
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Chris GralikeSpecialistCommented:
ps do the same against your dns server...

Regards,
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Chris GralikeSpecialistCommented:
Well it looks like you solved the problem yourself, that wasnt me :P

Happy it works :)
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