The OUIFilter.cfg file allows you to enter more than the first three octets of a MAC address if necessary to narrow down the phones – or even a specific user’s phone.
For example:
00.10.49 ShoreTel <-- This will show all ShoreTel phones in the environment
00.10.49.28.4B.5C Bob’s ShoreTel 230 <-- This will identify a specific phone
If you have phones and network equipment that both use the same MAC prefix (OUI), then use the next digit to narrow it down:
00.23.1B.6A Cisco