We have and ISA and a ISM module in our 7140. The point is to off-load some of the CPU cycles for the IPSEC encryption to the ISA cards. But I can't get one of the cards configured correctly. Here is what the config looks like:

controller ISA 4/1

!

controller ISA 5/1

encryption mppe

When I go to the 5/1 interface and type 'no encryption mppe' it accepts the command, but doesn't change in the config. Does anyone have experience with this? Do I need to reboot the router for this change to take effect? I hope not, because it takes the router 30 minutes to reload.