How To Set It Up with Tap Device
This is only applicable for having OpenBSD as Guest OS on Arch Linux as Host OS. I created simple bash scripts for all the below steps and then executed them from the terminal:- Done in host OS: Create a tap device and allow permission to the user, set the device up, assign a manual ip address to be used by the guest OS (in my case, it is 192.168.1.2), and forward the ARP proxy to the tap device.