#+TITLE: Creating a VPN Gateway with OpenBSD
#+DATE: 2020-07-11T13:48:25-04:00
#+DRAFT: true
#+DESCRIPTION:
#+TAGS[]: openbsd openvpn
#+KEYWORDS[]: openbsd openvpn
#+SLUG:
#+SUMMARY:

Say you have an account with a VPN provider. Maybe there are a limit
to how many connections you can have with one account, and you want to
put more machines than you have connections on the account. Or maybe
you want to put a large number of machines of the connection,
including maybe FreeBSD Jails, LXC containers, or VMs, and you don't
want to download the VPN profiles, and sign in and configure them all
individually.

The solution I came up with to this problem is to setup a VPN gateway
on my network using [[https://www.openbsd.org/faq/pf/][OpenBSD]]. Any device that sets that machine as it's
gateway will automatically get its traffic tunneled through the VPN
connection. It's also setup such that if the VPN connection ever drops
or gets killed for any reason, the traffic will stop and won't be able
to reach the internet. Thanks to this I don't have to worry about the
traffic ever leaking out through my residential gateway should OpenVPN
decide to close the connection. Sort of like a "kill switch", as some
companies market it.

The process for this is actually simple enough, thanks to OpenBSD's
[[https://www.openbsd.org/faq/pf/][PF]]. To replicate my setup you'll need a dedicated machine running
OpenBSD. You'll have to choose an appropriate host, taking into
consideration how much traffic you plan to put through it, the speed
of you VPN connection, and the speed of your home internet
connection. Anything from a virtual machine or a low power single
board PC will do in most cases, as home internet connections generally
aren't the fastest. If your internet connection is fast enough though,
you may consider [[https://blog.lambda.cx/posts/installing-openbsd-on-pcengines/][installing OpenBSD]] on a [[https://blog.lambda.cx/posts/pcengines-comparison/][PC Engines APU2]], as they're
affordable, have gigabit Ethernet, and great OpenBSD driver support.