I have a 9620L VPN phone on an IPOffice 500V2 running 6.0.18 (yes, I know, its older) on a Sophos UTM 9 router. The VPN establishes, but I get Discover xxx.xxx.xxx.xxx. I have tried everything I know to get this up. Here is the odd thing. If I upgrade the firmware on the phone to 3.2 or higher, I can ping the phones VPN Pool IP from the main site. And I see it in Monitor, just not registered and it lists as No Phone. I see the MAC and everything. The screen says phone... connecting.... phone... connecting and flashes back and forth. And I get the error "ERR: TPKT Recv: Length 2106 bad - bigger than buffer" in the monitor traces. If I allow it to downgrade via the VPN to any of the 3.1x firmware, it connects long enough to install the HA96xx firmware, reboots, then I no longer can ping it or see it. The VPN is still up, but it seems dead to the network. I don't see it in monitor, and I don't even see any 96XXUpgrade.txt requests. And I can't ping it. I have tried firmware 3.11, 3.13, 3.14, 3.22, 3.24. I have tried every combination I know in the router's firewall. I have tried adding all IP ranges in trusted networks. My router is also the VPN router and I have the default 0.0.0.0/ 0.0.0.0/ 192.168.10.1/ LAN1 in the IP routes on the IP Office. I even had Sophos look into it. I loaded a VPN client on my PC with the same settings, and I am able to establish a VPN and access their full LAN. Any suggestions???