The Communication Manager main server has a default module ID of 1. You can configure the Module ID on the Server Role page. Each survivable server has a unique module ID of 2 or greater.

The module ID must be unique for the main server and all survivable servers. The MID is administered as the Cluster Identification Number (CLID) in the Survivable Processor screen.

Each module receives a module identifier (MID) when a license file is created. The MID is referred to as the CLID in Survivable core servers. A CLID uniquely identifies a single cluster so that each server in a duplex pair can have the same CLID.

For the survivable core server to register with the main server, the MID of the survivable core server must match its administered CLID. The CLID is administered in the Survivable processor screen. For more information about how to administer a survivable core server using the Survivable processor screen, see Survivable core server administration.