I've got a handful of new 891 remote office routers that I've configured to
connect via two concurrent GRE/IPSec tunnels back to two different home offices.
One home office provides data for the PCs, and the second home office provides voice for Cisco phones.
I've got the 4-port switch in the 891 router partitioned into two VLANS, one for voice-only, the other for data-only.
Each VLAN gets routed back to the appropriate home office via its own GRE/IPSec tunnel.
I've got a dhcp enabled in each 891 to provide address and option 150 service for Cisco phones at the remote offices and everything is working OK except when a user at the remote office plugs a PC into one of the PoE phone ports on the 891, and the dhcp server doles out an address to the PC and then the user can try to prowl around on my voice network, which I need to stop.
Is there a simple way which I can comfigure the local dhcp service running in IOS on the 891 only respond for Cisco phones only, and simply not give out any address to any other non-phone device ?