According to Cisco, all three images you listed will support ISL VLANs on FastEthernet interfaces. If you're trying those images on a FastEthernet interface and it still isn't working, then I don't even have a guess as to what might be wrong. If it's an option, perhaps upgrade to something higher in the 12.1 train or--even better--12.2(2)T or 12.2(1a). Those seem to have quite a few bugs fixed and my impression is that they're fairly stable. Take that with a grain of salt, though, we haven't had 12.2 running for very long yet. Whichever release you decide to get, you need a "Plus" image to get ISL. HTH, John On Fri, 15 Jun 2001 19:13:53 -0400, JC wrote: | I have a 2620 router hooked up via fast ethernet to my Cat 5005, I want to | do intervlan routing using ISL encapsulation. Every time I specify a | subinterface and type in the word encapsulation ? I receive unrecognized | command. I have used the three images below on the 2620 to no avail. Does | anyone know what could be wrong. The first two images I have listed here | are IP Plus images, why can't I get it to go. Well I'm done for tonight. | Please comment with any help you can give, is there a specific IOS I should | be using. | | c2600-is56i-mz.120-3.T3.bin | | c2600-is-mz.121-1.bin | | c2600-js-mz.120-3.T3.bin | | | | Thanks, | | JC | | | | _______________________________________________________ Send a cool gift with your E-Card http://www.bluemountain.com/giftcenter/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=8806&t=8797 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]