In the factory default state, Peplink (Pepwave) routers have a LAN address of 192.168.51.1, act as a DHCP server on the 192.168.51.0/24 subnet, and are in the route mode of a typical router - Network Address Translation (NAT) mode.
IP Passthrough mode, simply stated, disables the router functionality and provides the cellular WAN address directly to one attached network client.
To enable IP Passthrough mode, first login to the device. The Dashboard will be displayed. Click the Details button next to the Cellular WAN connection as shown below.
The "Connection Details" window will be displayed. In the "General Settings" section, select the option for "IP Passthrough".
Click the "Save and Apply" button at the bottom of the Connection Details window. Reboot the Peplink device and the attached network client. The network client connected to the Peplink LAN interface will now receive the cellular WAN IP settings via DHCP. For greater stability, INS recommends statically configuring the Ethernet settings of the device behind the Peplink modem to avoid DHCP lease timeouts.