IP pass through or IPPT support


Is there any hardware which supports IPPT like the Netgear LB1120 and the Cradlepoint devices?


All devices with 2 or more Ethernet ports should support it.

  • You would simply change the Switch ports desired - to all be on the WAN's VLAN. I surmise you also would desire to disable the DHCP client on WAN. You can do this on the web GUI under Network > Switch and disable DHCP at Network > Interfaces.
  • If the ports are different PHYs, you would bridge them together.

Let me rephrase, is there any hardware available which allows 4g wan and Lan to be bridged.

If the 4G device contains a (NAT) router then you can disable DHCP on the openwrt lan and connect a lan port to the 4g wan. The lan interface needs to be changed to dhcp client or you need to configure a static address in the subnet of the 4G router lan. You don't need the wan port and interface on openwrt in this case and can use it as a lan port by following the instructions by above.

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Is there any hardware available to buy which supports this?

As I noted:

As long as the device has 2 available ports for your aircard (which is USB-based) and LAN Ethernet (RJ-45), you should be able to:

  • Setup the PHY connecting to the aircard (USB Ethernet)
  • Bridge them to VLAN1
  • Add ports to Switch
  • Disable LAN DHCP

See: https://openwrt.org/toh/views/toh_available_864

In TOH there are 5 device listed with cellular functionality, https://openwrt.org/toh/views/toh_available_864?dataflt[0]=modem_%3DMobile%20Wireless%2FCellular%20network

Out of these GL.iNet cannot bridge between WWAN and LAN. I dont know if any of the remaining 4 has this functionality.

Is it a requirement for you that the 4G be built into the router?

Will USB or miniPCIe work?

What if the IMEI is blacklisted?

Not necessarily, but an integrated device is easier to handle.

My use case is to use an IPPT device to give out a WAN ip to pfSense. pfSense is not great at handling USB devices but can deal with ethernet very well.

This is a software limitation of the OEM...it appears....this has nothing to do with OpenWrt. In fact, the thread discusses upgrading the OEM firmware to gain that functionality. It also seems the the orginal OP said that it would not work, because they planned to Double NAT...


trumee 2018-07-23 14:49:36 UTC #14
Unfortunately port forward is not an option due to issue with double NAT.

I hope you know, you cannot NAT if you plan to get an IP from the cellular device on the VLAN1.

Also, there's a discussion of Carrier-Grade NAT. If this is your problem, you cannot overcome this issue unless you request a Public IP Address from your Cellular Provider.

EDIT: also, i suggested miniPCIe because if you wanted to remove the WiFi card, you could insert the cellular modem in its place. I would consider that an integrated device...

Ok, you seem to be suggesting that openwrt on that GL.iNet device can be setup for IPPT. If so that would be great.