Larvitz Blog
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Welcome to Larvitz Blog! I’m Christian, a Senior Consultant by day and FreeBSD enthusiast by night, with over 20 years in enterprise IT. Here I write about FreeBSD jails, PF firewalling, self-hosting, Linux system administration, and anything that’s cleanly engineered. Most articles are hands-on guides born from running my own infrastructure, from dual-stack networking and Ansible automation to hosting a Mastodon instance on FreeBSD.

Have a question or want to discuss something? Find me on the Fediverse at @Larvitz@burningboard.net. I’m always happy to chat!

#freebsd Articles

I Wanted an IPv4 Toast and Accidentally Built an IP Service

At 10:15 this morning I added a gently condescending toast for IPv4-only visitors to hofstede.it. It called ipify, which felt increasingly inappropriate for somebody operating an ASN. Three hours later I had written a Rust IP-information service, put it behind Caddy, given it three DNS names, and deployed it in its own dual-stack FreeBSD VNET jail. This is how a two-line dependency became infrastructure.

bhyve Inside a Jail: The FreeBSD Feature Nobody Uses

A jail shares the host kernel, so sooner or later you need a real virtual machine. bhyve has been able to run inside a jail since FreeBSD 12.0, and almost nobody does it. This is the full build from my production hypervisor: the devfs ruleset, the four things that have to line up, the two-tier bridge topology, and an honest account of what allow.vmm does and does not buy you.
  • Wed 12 August 2026
  • Linux

Chezmoi and Git: Dotfiles Without Pretending Every Machine Is the Same

A Git repository is a good place for configuration files, but it does not know where they belong, which permissions they need, or why a work laptop and a home server should differ. Chezmoi adds that missing layer. This is how I use both tools to manage fish, Git, Neovim, GnuPG, OpenSSH and Atuin, including the recovery command for the inevitable day I edit a live file directly.

Three Test Jails on a 512 MB Free-Tier VPS

A bug report against my jailexec connection plugin needed a real FreeBSD jail to reproduce. An idle free-tier VPS with 512 MB of RAM turned out to be plenty: pkgbase provides a 33 MB base userland, persistent jails need no idle processes, and three Python-equipped test targets added only 1.1 GB of disk use. This is the build, including the two sharp edges that cost me twenty minutes.

Running Your Own AS: An IXP over VXLAN, IPv4 on the Overlay, and a Config Spring Clean

Part 5 of the AS201379 journey: joining EVIX, an internet exchange that hands out VXLAN tunnels instead of switch ports, carrying a routed IPv4 /29 across the IPv6 overlay with PF policy routing, the dual-FIB routing that makes a VPS work as both a normal host and a routed AS site, moving the downstream MikroTik onto WireGuard, and a long-overdue cleanup of four routers’ worth of accumulated configuration.

Building My Own TV Station: ErsatzTV in a FreeBSD Jail, With Intel Hardware Transcoding

Being ill for a week taught me that a large Jellyfin library is not entertainment, it is homework. ErsatzTV turns a media library back into linear television with real channels and schedules, but it only ships for Linux, Windows, and macOS. It is a .NET application driving ffmpeg, so I built it in a FreeBSD Bastille jail instead. One missing conditional was all that stood between FreeBSD and Intel VAAPI hardware acceleration.

A Caching FreeBSD Mirror for DN42: nginx proxy_store, pf, and a Dual-Homed VM

Patching FreeBSD machines inside the DN42 overlay network without giving them clearnet access - a dual-homed VM that lazily caches pkg.freebsd.org, update.freebsd.org, and release tarballs from ftp.freebsd.org with nginx proxy_store, follows CDN redirects server-side, and serves everything over IPv6 into the mesh. Now also available as a public DN42 service at bsdmirror.chofstede.dn42.

Upgrading FreeBSD 15.0-RELEASE to 15.1-RELEASE: The Official Paths

FreeBSD 15.1-RELEASE is here, and the official upgrade instructions depend on whether your system uses distribution sets or packaged base. This guide walks through both supported paths, covers the boot-loader update, and explains the configuration merging process - all based on the official 15.1 upgrading documentation.