How to Allow Internet Access for the Backend Servers in Two-Arm Proxy Mode Last updated on 2018-05-31 00:36:03 The procedure for allowing access for the backend server in two-arm proxy mode is based on the firmware version you are using.Users with Firmware Version 9.0 or earlier click here.Users with Firmware Version 9.0 or later click here. Last updated on 2018-05-31 00:36:03