VLANs with Linux, NFTables and Ubiquiti Unifi

While setting up my new Ubiquiti Unifi WiFi access points, I spent more time than I’d like to admit troubleshooting my new guest network before I got it to work, so that topic is the basis for this post. The problem I encountered turned out to be completely trivial and I’ll spend a paragraph further… Continue reading VLANs with Linux, NFTables and Ubiquiti Unifi

Deploying a Ubiquiti Unifi appliance with Ansible

I finally got tired of my old 802.11n Apple Airport Express(!) that has been serving the kitchen part of our house with an Internet connection for many years. Effectively it tops out at ~100Mbps speeds and has pretty poor range. It is being replaced by a Ubiquiti Unifi6 Lite access point. In preparation for this,… Continue reading Deploying a Ubiquiti Unifi appliance with Ansible

DNS, DDNS, and DHCP on a Linux router – Part 2

(Update 2022-07-15: I have set up a Git repository containing the example files used in this post to simplify understanding of the file and directory structures.) In a previous post I described how to set up a simple and efficient router and perimeter firewall on just about any computer. What I kind of glossed over… Continue reading DNS, DDNS, and DHCP on a Linux router – Part 2

Build your own router with nftables – Part 1

Introduction A few years ago, Jim Salter wrote a number of articles for Ars Technica related to his “homebrew routers“. Much of what he wrote then still stands, but time marches on, and now that I rebuilt my home router, I figured the lessons should be translated to a modern Ubuntu installation and the more… Continue reading Build your own router with nftables – Part 1

Email address tags in Postfix and Dovecot

What if you could tag the mail address you provide when registering for various services to simplify the management of the inevitable stream of unsolicited mail that follows? If you could register myname+theservicename@mydomain.tld it would make it very easy to recognize mail from that service – and it would make it easy to pinpoint common… Continue reading Email address tags in Postfix and Dovecot

IPv6 guests in KVM

I’ve been experimenting with IPv6 at home, and spent some time trying to get it working in my virtual machines. The first symptom I got was that VMs got a “Network unreachable” error when trying to ping6 anything but their own address. The cause was a complete brainfart on my side: We need a¬†loopback interface… Continue reading IPv6 guests in KVM