Well that is crap! The 1720 has a 10/100 interface.

If you tab it will complete the Encapsulation command and then tell you it is unrecognized.

Thanks for all your help

Ouch!

Sorry, I put 1721 into the Software Advisor and "IEEE 802.1Q VLAN Support" appears in the features list. I put 1720 in, and it does not.

My mistake was to assume it was something to do with 10 Mbps vs 100 Mpbs. I guess I should have checked that fact as well. There be some other reason, but I don't know what. I'll try and choose my words more carefully next time.

Sorry, I cannot answer your question.

Kevin Dorrell

Luxembourg

O sorry I guess it read wrong or i wrote it wrong. I meant that the router is a piece of crap. It has a 100 mbps interface it should do Intervlan. I really appreciate your help, I sorry if it seemed like that was directed at you.

It really is weird that the 1720 cant do trunking, while the 21's can, but I guess Cisco probably used totally different hardware for the ethernet interface. One that supports trunking, and one that does not. The price difference is not that high either...

Actually, 802.1q does not require 100Mb or more. Its not documented as a requirement.

It is ISL that does require Fast Ethernet.

What you find on the website documented is what TAC will support. Some hardware, and software combinations will support things that are not documented.

When you know or find some thing like this its nice, but just remember you are on your own when you have probs. Also newer releases will probably have it removed so if you are thinking about upgrading for a new feature you might lose your hidden feature.

2610 and 2611 with IP PLUS I believe supports 802.1q but don't remember which code release.The 7206 I/O controller that is only 10Mb also did but I don't remember what code.

I think I recall the 1720 also had an IOS that had 802.1q, but can't remember which one.

Daniel