The operational VR for a secure IP tunnel is the VR in which a secure IP tunnel exists.
The IP address and mask associated with a secure IP interface exist only within the operational VR under which the interface is declared. The VR defines the network prefix, which is reachable through the logical IP interface.
A secure IP tunnel is always a member of one and only one operational VR. Therefore, the operational VR attributes are mandatory for any secure tunnel. These attributes include: