Configuring Raspberry Pi as a VPN gateway using NordVPN with best server selection (Pi-hole with DoH setup optional)

This is going to be a quick tutorial (/self-reference) to set up Raspberry Pi as a VPN router for NordVPN. I ran into so many issues (!) specially with the kill-switch part, so just wanted to write this up in case someone else is looking for the same. Obviously there are better ways of getting this done documented out there, but I wanted a custom setup with a few modifications as you will see. As an add-on, I installed Pi-hole for ad & malicious domain blocking with DNS over HTTPS (DoH), with the DNS queries now tunneled over VPN.

Restoring real IP address from Cloudflare in logs when using nginx-proxy with Docker

While using nginx-proxy from jwilder with Cloudflare, one of the common issues you run into is that the logs contain the Docker internal IP rather than the real external IP passed by Cloudflare.

Internal IP

Note - During my tests, this only applies when nginx-proxy is run as two separate containers - jwilder/docker-gen and the official nginx image. Also, I have whitelisted my server to accept connections only from Cloudflare IP range to port 443 (Full - Strict config).

Wi-Fi packet sniffing / monitoring on Windows using Raspberry Pi - inspired by Wimonitor

Wimonitor is a wonderful product from Hacker Arsenal that saves pentesters the hassle of having to configure VMs, carry compatible wireless cards that support monitor mode etc. and comes with a web interface to do the configurations. It gives you the flexibility to plug in the device into the Ethernet port and start Wi-Fi monitoring on any OS. Basically it is a tp-link TL-MR3020 router with a custom firmware that does all the monitoring part and sends the packets to the host laptop (or Mac !) where you can start Wireshark and concentrate on the packet analysis.

I haven’t got one yet, but have been hearing good reviews about the product since launch. The shipping cost to EU is a bummer :(. Hopefully they will start shipping from EU soon.

Meanwhile - why not try this on a Raspberry Pi ?

Connecting USB devices to VirtualBox using USB 3.0 ports

This took me quite a bit of time to figure out, hopefully someone finds the steps useful. Many of the wireless cards that support monitor mode are all USB 2.0 devices - e.g. Alfa AWUS036NHA, TP-LINK TL-WN722N and run into problems while connecting to newer laptops that come with only USB 3.0 ports. If you try to connect the wireless card to the USB 3.0 port and then try to attach it to VirtualBox VMs like Kali, it will not work straightaway.