I have a 2621 router running IOS version 12.3(13) and I am trying to set up802.1q VLAN on a sub interface. Well when i go down to the sub interface and type the following command.. "encapsulation dot1q 1 native"; I get an error. I hit the ? for all the commands available and the encapsulation is not available. I have confirmed I was down in the subinterface. I check another 261 that I have in production running ios version 12.2(16a) and it does have the encapsulation command. Now the firts router is running some nat transalations, but that shouldn't have anything to do with it, right?