Advice Needed in Setting up a VPN Client/Server/Gateway(?) on Raspberry Pi

VPN
1

I’m thinking of doing this project and seeking your advice.

I want to offload my poor AC88U and set up a Raspberry Pi 4B as a VPN server with two objectives:

  1. Offload my poor AC88U. The throughout suffers when the VPN client is live.
  2. This is solely served for outgoing traffic. I don’t need to access my network from the internet.
  3. Allow split tunnelling: some of my outgoing traffic using VPN service, say Surfshark, while the other pass through as normal.

First off, does running a standalone VPN server (using Raspberry PI 4) make sense? Or I need sth more powerful? What is the right name to this device I’m going to make? Is this really called VPN server or client or sth else?

Also, I’m planning to pick OpenWRT rather than Raspberry OS as I believe OpenWRT is a pure networking software; there won’t be overheads draining the CPU power due to any unnecessary running programs. Any better alternatives I should look into as well? If OpenWRT, what module should I look into?

I asked these over in ChatGPT & Gemini, but they didn’t give me the info I need. Maybe, I was asking the wrong questions. How should I rephrase my wordings to get a better answer in future.

Most importantly, where to look up for the tutorials/material for this project? I don’t want to trouble you guys with questions in every single step I made.

Thanks in advance for all your info and advice.

2

Try Wireguard, it’s more efficient than OpenVPN. A Pi 4 should work well.

3

Thanks. I want to, but I don’t know to get the NordVPN linux app to work; all I can do is to use OpenVPN to work with NordVPN config file.

Any clues? Thanks.