Which version of the 2900? Are you referring to the older 2901 switch that runs CatOS? Or to the newer 2900XL series that run IOS? I know the 2901 running CatOS can trunk only on the two FastEthernet ports on the Sup. As far as the 2900XLs, they can trunk as evidenced by the following output:
SWITCH#show ver Cisco Internetwork Operating System Software IOS (tm) C2900XL Software (C2900XL-H2S-M), Version 12.0(5.1)XP, MAINTENANCE INTERIM SOFTWARE Copyright (c) 1986-1999 by cisco Systems, Inc. Compiled Fri 10-Dec-99 10:57 by cchang FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
