For example, we have CUCM 9.1 and 2 divisions:
- Division1 with Network_Subnet1 and extensions 1XXX
- Division2 with Network_Subnet2 and extensions 2XXX
How can I allow registration of phones with extensions 1XXX (or Device Pool DP_Div1) only from Network_Subnet1 and deny registration from Network_Subnet2?
The only way I can see of doing this would be to maintain two lists of the phones MAC addresses (i.e. list 1 contains phones with 1xxx extensions and list 2 contains phones with 2xxx extensions) and then configure your network infrastructure such that only the 1xxx phones can connect to the VLAN1 ports and only the 2xxx phones can connect to the VLAN2 ports.
802.1x with MAC Authentication Bypass as described at the link below may allow you to do this.
However it may be costly to set up and painful to manage!