I recently expanded the DHCP pool for a customer that was already on a /22 LAN net (192.168.220.1 - 192.168.223.254), the DHCP just wasn’t using it all (only using using 192.168.220.x-192.168.221.x).
A Polycom 550 began behaving strangely afterward. In EPM, it is shown with the IP address as usual, but is “:UNREACHABLE”. It had gotten a DHCP address is that newly expanded range at 192.168.223.x. I could ping it and log into the web GUI without issue, but it couldn’t call out, didn’t ring inbound, etc.
I manually set a 192.168.220.x IP on the phone and it worked immediately. I double-checked the PBX, only 1 IP address configured on 1 NIC, and it was indeed already set to /22. This is a flat net, the only VLAN in place is for Guest WiFi, and no static routing in place. All other devices in that new address space (PCs, cell phones) work normally.
Any ideas on why the Polycom clearly “talked” to the PBX but showed up as UNREACHABLE in that new address space? Thanks!