How to (not) build a Router


For some time now, I wanted to build my own router. Mostly because a) I like challenges, b) I like to try out new things, and c) like to fiddle around with stuff. Plus, I was sick of my Fritz!Box (German run-of-the-shelf router, which is common here).

I wanted to control my network. So I decided that "It can't be that hard!"™ to build your own router (with firewall, DHCP, and all the bells and whistles).


The first iteration of the router, built in early summer 2019 was pretty straight forward:

All in all, it's an okay-ish build, which doesn't kill it, but runs "decent".


I'm using OPNSense. No experiments here. It works pretty good. However, you will need to be able to get your head around some specialties. But all in all, yes, I like it. Looks like that now:

OPNsense Dashboard

Let's take a closer look at the system information, shall we?

OPNSense System Information

The system is running at an average of 50 to 60 percent. With 42 °C, it's not overly warm, so it runs pretty ok.

Now, for 2020, our first 12 months of the cable internet contract will have passed. We will then be able to make a new contract, thus increasing the speed for the WAN side.

Which leads me to the next point. Currently, we are running a 200 MBit/s on the WAN side, which is ok for now, but soon we'll be going for a whopping 500 MBit (maybe 1 GBit, depends on much I'm willing to take).

Rest assured, that the tiny Celeron will struggle with a GBit line, if (and that's something I'd like to keep) the Intrusion Detection and Intrusion Prevention System is still running.

Upgrade the System

Here is where the fun starts. I want to upgrade the system. I had many ideas - a lot of which got destroyed on the way. So stay tuned for the next follow ups of this series!

Next part: [002] Picking the right hardware