They use the same SRP. From the install doc -
6. In the Setup options dialog box, perform the following actions:
• Click Install a standby BlackBerry Enterprise Server to set up high availability.
• In the Additional components list, select any components that you want to install with the standby BlackBerry Enterprise
Server.
• To permit administrators to log in to the BlackBerry Administration Service and BlackBerry Monitoring Service using
their Microsoft® Active Directory® credentials, in the BlackBerry administration list, click Use Active Directory
authentication.
7. In the High availability settings dialog box, select the primary BlackBerry Enterprise Server that you want to assign the
standby BlackBerry Enterprise Server to.