We have a UCM 6510 configured in dual network mode - LAN1 is connected to external network (with public IP on it), and LAN2 is connected to LAN. External network (LAN1) is only used for some sip trunking, and LAN2 is the default interface.
The phones (they are in LAN, obviously) are configured via Zero Config. However, PBX sends its “LAN1” IP (public address, unreachable for the phones) as a “sip server” address, instead of the LAN2 IP.
In dual mode (when the PBX has two IP addresses), is there a way to force, which “SIP Server” IP to send to the phones in zero config? Because by default PBX is sending a wrong one.
The only fix we found so far is to manually set the right IP in the “SIP Server” custom field for each phone, but unfortunately this field is not configurable globally and we have to set it per each phone.