0

I have a Raspberry Pi 4B with the latest Raspberry Pi OS intalled. So I have a USB dongle which is connected to the internet and shows up on Raspberry Pi as 'eth1' interface. I want the lan port of Pi to output internet which goes into the WAN port of my TP-Link router and then I connect all my devices to the router. I followed the guide here on this page https://stackoverflow.com/questions/41766414/use-raspberry-pi-as-a-bridge-b-w-mobile-and-router#:~:text=To%20do%20so%20you%20need,should%20be%20recieving%20internet%20connection The bridge was set up successfully and I could access the internet from router. However I couldn't access Pi over SSH which is something that I need since it is a headless setup.

The whole setup -

USB Dongle (internet) [DHCP] -----> RasPi 4B ------> TP-Link Router (DHCP) ----> Devices (Laptop/Phone)

Please tell how should I proceed with this

2
  • Without knowing what type of router and configuration, it sounds like there's an issue with IP ports being blocked to addresses outside of the routers control. Is it necessary for the Pi LAN to be connected to the router WAN? I am wondering if you can access the Pi via a network port on the router?
    – jwbradley
    Dec 7, 2020 at 16:29
  • Have you tried giving the bridge an IP address (in the range that is valid between the dongle and TP-link)? Dec 7, 2020 at 16:52

1 Answer 1

2

The wired port on the Raspberry Pi provide a connection to an ethernet network. The WAN (Wide Area Network) port on the router provide a connection to a port (whatever it is) from your internet provider to get into the internet. This port does not connect to an ethernet network. This means that you have to connect the RasPi with an ethernet cable to a usual LAN (Local Area Network) port of your router which can also be used by other devices on your local network. If it still does not work, then it could only be an addressing or routing problem on your local network.

UPDATE:
According to a comment it seems there is still a confusion with the terms WAN and LAN. To understand what I mean, here is a Quote from Wikipedia Wide area network:

it may be best to view WANs as computer networking technologies used to transmit data over long distances, and between different networks. This distinction stems from the fact that common local area network (LAN) technologies operating at lower layers of the OSI model (such as the forms of Ethernet or Wi-Fi) are often designed for physically proximal networks, and thus cannot transmit data over tens, hundreds, or even thousands of miles or kilometres.

The RasPi is not able to manage this on its LAN port.

6
  • If you configure a RPi as a router, nothing prevents you from connecting another router's WAN port to the RPi's ethernet port so the other router gets internet access via the RPi.
    – Ole Wolf
    Dec 7, 2020 at 10:09
  • @OleWolf Seems you are also confusing WAN with LAN. Please take notice of the update in my answer.
    – Ingo
    Dec 7, 2020 at 10:42
  • What I'm saying is the RPi can use the USB dongle for a WAN (that it, is to get Internet access). The RPi then routes traffic through its ethernet port, which the secondary router can now consider its WAN, and so the router can provide internet access on its LAN ports. The OP's setup is indeed possible.
    – Ole Wolf
    Dec 7, 2020 at 11:34
  • @OleWolf Most router have one or more LAN ports and one WAN port to connect to an internet provider. If you connect the RasPis wired LAN port to one unused LAN port on the router then of course it is possible what you think. But please, please, please understand that you cannot connect the WAN port to a LAN port with success! This only fit physical.
    – Ingo
    Dec 7, 2020 at 12:18
  • My impression is that the OP needs a USB dongle for internet access but the router doesn't provide this option. So, the OP intends to insert the RPi in-between the two--that is, the RPi becomes the internet provider as far as the router is concerned. And so you can certainly connect the router's WAN port (assuming it's a home router) to the RPi's ethernet port. One can also chain multiple home routers this way.
    – Ole Wolf
    Dec 7, 2020 at 12:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.