Something's up with the DNS on my network and I'm confused. I have 2 Windows 2008 servers (one non-R2, one R2) with AD services installed, each are domain contollers, global catalogs and running DNS server. Forwarders on both servers are set to my ISP's DNS server. All forms of internet access work across the network. Workstation's DNS point to the R2 server. There is also a member server with Exchange 2010 installed and sort of working. I'm having name resolution problems with some domains (in this case, cogeco.ca). Check these results from nslookup, same on any machine on the network: C:\Users\Administrator>nslookup gmail.com Server: UnKnown Address: 192.168.1.66 Non-authoritative answer: Name: gmail.com Address: 173.194.32.83 C:\Users\Administrator>nslookup cogeco.ca Server: UnKnown Address: 192.168.1.66 DNS request timed out. timeout was 2 seconds. DNS request timed out. timeout was 2 seconds. *** Request to UnKnown timed-out ??? The IP address of the DNS server is the correct internal DNS server with a single forwarder to my ISP. Why is it able to look up gmail.com but not cogeco.ca? cogeco.ca is a major Canadian ISP, not just Fred's place with a bad DNS server. Could this be a problem with my ISP's DNS? Any input appreciated, thanks!

Try changing the forwarders to 4.2.2.2 and 4.2.2.3. I have had several problems ISP's DNS servers in the past and this always fixes my issues. Make sure you clear the DNS servers cached (in the DNS mmc) and any DNS client cache before trying again (ipconfig /flushdns)

Test via nslookup and bypass your local DNS server. Type the following lines one at a time. nslookup server <isp dns ip> set type=soa set timeout=5 cogeco.ca This will look for the SOA record directly from your ISP DNS Server record with a 5 second timeout, you may need to do this from your DNS server (depending on your firewall config). Repeat for the gmail.com record as well. If both work, it may be a DNS timeout lower that setting a retest. If gmail works and cogeco.ca fails, its most likely your ISP.

Solved, thanks! Looks like I need to talk with my ISP.