10.8 Is it possible to set a password on the remote support modem (ldev 21)? If so, how?

Go to the console and hit ctrl-b. At the CM> prompt select ER (enable remote access). It will ask if you wish to make any changes. Just answer yes and it will then prompt you for the password. Follow the rest of the directions and you should be ok.

One disadvantage of this is you will be required to keep the console port enabled. If enabled, Predictive Support will not be able to dial out using this modem.