Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

Cisco 2621 and 802.1Q

I have been trying to configure 802.1Q -capable subinterfaces for Cisco 2621 router. I have only two fast ethernet interfaces. Flash 8 mb, RAM 32 mb.

When I try to configure an IP address for subinterface, IOS says that the "encapsulation needs to be configured first".

I am using IP/FW/IDS software, tried it with many versions, been running mostly with 12.2.7b. I cannot even see the command "encapsulation" in subinterface config mode!

Help GREATLY appreciated!!

Cisco Employee

Re: Cisco 2621 and 802.1Q

As per feature navigator, you need the T train for IEEE 802.1Q VLAN Trunking. Try upgrading to 12.2(11)T

Also IP Plus feature set is needed. Refer to the following page


Re: Cisco 2621 and 802.1Q

Interestingly, I'm using 12.1(16) which supports 802.1Q, yet the feature navigator says otherwise.

Community Member

Re: Cisco 2621 and 802.1Q

IOS "c2600-io3-mz.12.2-7b" which is 12.2(7b) with IP/FW/IDS feature set does not cover "IEEE802.1Q VLAN Support" and "ISL VLAN". Sorry but you should try another version/feature set for the trunking router.

Cisco Employee

Re: Cisco 2621 and 802.1Q

You need to have an IOS which includes the PLUS feature set to be able to configure trunking. In other words, the filename must include an 's'.

E.g.: c2600-is-mz.122-7b.bin

CreatePlease to create content