DNS queries are not working on my routers. I'm going through a loopback adapter and pings to an external IP number work fine. But any DNS queries fail, both on the routers and on the Vbox guests.

The error I get is:
% Unrecognized host or address, or protocol not running.

The debug results and a Wireshark capture show the queries being sent, but nothing received.

I've setup the DNS and debugging per the Cisco instructions:
http://www.cisco.com/en/US/tech/tk648/t ... 525f.shtml

I've tried four different router configs all with the same result. I've setup DNS for both my 2wire router at 192.168.1.254 and Google DNS at 8.8.8.8.

Computer setup:
Windows 7 Pro x64
GNS3 0.8.2

IOS:
ip name-server 8.8.8.8
ip name-server 192.168.1.254
interface FastEthernet0
ip address 192.168.137.254 255.255.255.0
ip route 0.0.0.0 0.0.0.0 192.168.137.1
access-list 101 permit udp any any eq domain
access-list 101 permit udp any eq domain any

Router configs I've tried include the 3725 with c3725-ipbasek9-mz-124-18.

Since my primary goal is to simulate a real-world small business network, including software that monitors the router, this is not a good thing...

I figured it out... A problem with my firewall software: VIPRE Internet Security 2012. It seams to randomly block traffic from the GNS3 components. I've turned off the VIPRE firewall and turned on the Windows firewall and DNS is working fine. In fact, pings are getting through faster with Windows firewall.

Adding to the mystery is that VIPRE wasn't logging any of the traffic that it was allowing or blocking. Some day I may follow up with VIPRE tech support to troubleshoot, but for now I'm happy that it works.

Well you should check your network connection and router settings and finally update your firewall settings. If you want proper solution then you should take Microsoft Help & Support for best network support.