Question : Internet problems after Domain Controller Upgrade 2008 Server R2 x64

Alright.. here we go.

Upgraded a Domain Controller running Windows 2000 to a brand "new" Server running Server 2008 R2 x64, two of them.  

After I got done with the whole promoting and demoting process everything seemed to be working fine with no problems.

About 24-36 hours after the install was complete I started seeing a degraded slowing process of the internet.

Now I am having major lagging and timeout issues with accessing the internet.  When pinging on the LAN everything is super fast
when pinging outside the WAN, ie. google yahoo or whatever I get a delayed ping response.  Not a 23ms dealy but a delay prior to
anything being displayed, even before the ping repsonse.

After I type ping google.com I get a delay, then it cycles to the ping responses which are normal.

I've double checked that I have removed all the DNS Forwarders that pointed to the old DC.

- Ok fill me in.

Snowman

- NOTE:  I am on a domain, which has DHCP and DNS and AD and a secondary DC.

Answer : Internet problems after Domain Controller Upgrade 2008 Server R2 x64

Verify that your DC is the FIRST DNS server listed for ALL your domain computers INCLUDING both DCs.

Try pinging by FQDN (such as www.google.com) then use the IP supplied and ping again with that IP (and NOT FQDN).  This is just to help see if DNS resolution is the lag you experience.

Also, I would try NSLookup from the command line.

Note:  Your DC based DNS server should be listed as the name server when you launch NSLookup.

1. Resolve www.google.com and some other FQDNs. 
2. Change the DNS server to 4.2.2.1   
• >server 4.2.2.1 
3. Resolve the same list of FQDNs (including Google). 

Compare the speed of resolution between your server and the external server.

You may also wish to check your firewall logs and settings regarding DNS traffic to be sure that it is not an issue with the new internal DNS server.

- Tom