Created a simple bash script that checks if I am using my home public IP address or if I am using a VPN. I created this because I have been doing a lot of pentesting lately and I want to ensure that I am using a VPN before performing a pentest. This script performs an nslookup command against my Mikrotik provided DDNS service that is built into my firewall to get my home IP address. The script then executes curl --silent ifconfig.me to get the current public IP address of the machine running the script. The last part of the script compares the IP addresses and tells you if you are using a VPN or not. I could further expand on this to take some other action depending on if I am using my home IP address or not.

https://gitlab.com/joshsisto/linux_scripts/-/blob/7d2b19fd44cf0bc6d06e61212699f321845d7d0f/check-vpn.sh