+++ Please note: We got some connection issues at the start of the talk, which led to fragmented audio. This got better after a few minutes. +++ Five years ago, C3D2.de moved into a newly renovated building, receiving the opportunity to run the network infrastructure. We have been running kind of a non-commercial ISP for our neighbors since then. In this talk, I detail the design decisions that guided our network setup on both the Ethernet and the IP level. From the experience that we have gathered over time, I am going to lay out the design of our new NixOS-based setup to which I have migrated the complete codebase over the course of 2021. This is a public model network project: https://gitea.c3d2.de/zentralwerk/network/ about this event: https://pretalx.c3voc.de/rc3-2021-chaoszone/talk/9SCQVN/