When I configure a 7920 phone it often gives the error 'duplicate ip'. I can reset both the new phone, and the other phone already on the network with the same IP and one of them eventually gets another IP. This has only started happening over the last month or so. I can't find anything in DHCP that seems odd. I found other questions about this on here from last year, but never came to a conclusion.
Any help would be much appreciated.