Not sure if that title is accurate, this field is not my strong point. Basically I'm about to move homes. And in my new (temporary) home I wont have access to ethernet, plus my server doesn't have a network card. I was therefore wondering if it was possible to bridge a connection between my laptop to my server with an ethernet cable. This would obviously be a short term solution, but I'm wondering if it's possible and if so, how? Or is it better to buy a cheap network card?
My laptop is running NixOS and my server Unraid, if it should be to any help.
One way is to use iptables to forward the connection from the wireless interface through the ethernet interface. But I am not sure whether this is better than using the NetworkManager or a more specialized solution. I have used iptables for configuring WireGuard VPNs, but not for this specific use case.
However, my networking knowledge is not super fresh. I believe you need a special ethernet cable for this. A crossover ethernet cable. Then you have to manually set the IP address on both ends for that interface to something kind 192.168.0.1 and 192.168.0.2 Here's a quick how-to that shows an example.
Or... You don't have an individual router? Couldn't you just plug it in the router by ethernet cable?
I have a raspi 3b dedicated to being my wifi to ethernet bridge, the config is old and it runs rpi os but if your interested i can dig up how it works 🙃
You can do the same with $25 mikrotik device.
Infact, a lot of cheap wireless APs can connect to a wifi and bridge to ethernet, especially if they are running an openWRT fork (most cheapo wifi APs do)
I actually do have a spear rpi actually! However I was planning on running HomeassistantOS on it. But could do what you do as a temporary solution. If you wouldn't mind and have the time to look up your solution I would highly appreciate it 🙌
Via WiFi, sry if that wasn't clear. I simply don't have access to the router as that belongs to the landlord. He has a separate network for me, but it's on his side of the house 😅
I think moving what you can to your laptop is the simplest approach depending on what you need. You will likely be without some stuff but it will be simpler to setup than a direct connection.
Of course if you have a ton of data that may not work.
Your description isn't very clear on what exactly you have, or what you need.
It sounds like you have wired NICs in both server and laptop, which will be physically close to each other, but your only connection to the Internet will be WiFi that you don't control. How accurate is that?
Next question is how do you want them to connect to each other? You can do a P2P wired connection, which is more complicated but fully isolates your traffic. It also means that, unless each device has a separate connection and an appropriate routing config, it won't be online to the Internet (unless you set up some form of connection sharing). You can also connect them to a router that has no Internet. Simpler than the above, but the same limitations.
You could easily and cheaply get a USB Wi-Fi NIC. The major downside is that all traffic will be going across the wireless connection, both ways. This makes it slow and unreliable.
You can also connect them to a modified router configured as a wireless bridge. DD-WRT and others can be configured in a different way than usual. The wireless router will provide wired LAN ports to your local network, but then use the wireless connection to connect to an upstream WiFi.
None of this has anything to do with Linux, BTW. Once you choose a path, you should be able to implement it in whatever OS (or multiple OSes) you would like. None of it is new or special. You might get more options if you post in the Homelab, Data Hoarder, or Self Hosted communities.