I have 4 sets of stacked 3750 switches (3 members each), 3 of the stacks connect to the 4th stack in a star pattern via an "cross-stacked Etherchannel" with 3 ports each. Each of the 3 ports goes to a separate stack member at both ends. IOS 12.2(25) software guide says Channel Group mode must be set to "on" for cross-stack Etherchannels. Is this mandatory? This configuration is currently running with Mode = active and I haven't seen any problems. Maybe I'm not looking in the right place. What kinds of problems will "mode active" introduce?