I configured NAT on a Catalyst 6500 Switch. I created a Vlan, defined it as NAT Inside and associated a few Switchports to it. I configured a Physical Port as a Routed Port and defined it as NAT Outside. I created an Access-list matching a Class A Private Address used on the NAT Inside Vlan Interface, and then defined a NAT Inside Source List to overload on the NAT Outside Interface. The problem I have is when I generate Pings from a PC on the NAT Inside VLAN Interface the pings are successful (NAT works). But when I try to do DNS lookup from a PC in the NAT Inside Interface DNS is not successful and specifically the NAT Process reports a failure in NAT translation. The report says the following "translation failed (A), dropping packet s=10.20.20.1 d=192.168.1.1". The DNS Server is located on the NAT Outside Interface.

Can anyone kindly give me a clue some missing configs. Firewall Services Module is disabled on the 6500.

Thanks.