Internal L2 GRE interface IP prefix represents the GRE interface IP prefix. SRCC's internal uses a GRE L2 tunnel, in which the interface is configured with a C class IPV4 address. The netmask for this ip network is 255.255.255.0. Thus the first 3 octets only are meaningful. The last digit replace with 1 if the final role is AP; with 2 if the final role is client.