Cisco ASA radius-common-pw command

When configuring a Cisco ASA device to function in conjunction with a RADIUS server for AAA, there is an optional parameter called radius-common-pw that can be configured.

This parameter is used internally by the ASA for its communication with the RADIUS server for all authorization transactions. The syntax is:

radius-common-pw string

In the context of RADIUS authentication, the authorization server requires both a username and password for each user attempting to connect. While the system automatically provides the username, the administrator must manually input a shared password. This password needs to be configured on the RADIUS server by its administrator to associate with all users authorizing through this particular system.

If a common password isn't specified, the system defaults to using each user's username as their password. However, this practice is not recommended if the RADIUS server is used for authorization elsewhere in the network, as it could pose a security risk.

So this configuration is optional, but the administrator of the RADIUS server must know what has been configured in order to correctly communicate with the ASA. Note also, that this password is used only for internal communication between the ASA and the RADIUS server, and only for authorization mechanisms. End users don’t need to know this password. They simply use their own credentials.