Welcome to Larvitz Blog! I’m Christian, a Cloud 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!

Networking Articles

Thu 30 July 2026
Networking

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.

Mon 08 June 2026
Networking

IPv6 Foundations: The Internet Protocol You Should Already Be Using

A laid-back tour through the basics of IPv6: how the addresses are built, how to shorten them without losing your mind, how they map onto the IPv4 you already know, and how hosts configure themselves with SLAAC. Plus a short sidebar on NDP and why blocking ICMP on an IPv6 network is a self-inflicted wound. The premise throughout: IPv6 is the current internet protocol, IPv4 is a relic we are still dragging around, and dual-stack is a burden, not a destination. Updated 2026-06-12 with reader Q&A on privacy addresses, banning abusive clients, NAT64/DNS64, and port forwarding.

Fri 24 April 2026
Networking

Joining DN42: A MikroTik Border, Three WireGuard Peerings, and a FreeBSD Jail in the Hobbyist Internet

Building a DN42 node from scratch - registering AS4242422539 and fdce:73f7:a2dc::/48 in the registry, configuring a MikroTik border router with three WireGuard peerings and BGP filters, running a FreeBSD bastille jail as authoritative DNS for chofstede.dn42, and reaching the rest of the hobbyist mesh in two hops.

Thu 16 April 2026
Networking

Running Your Own AS: Direct Hetzner Peering, a Fourth Edge, and Bringing the Home LAN into the Fabric

Part 4 of the AS201379 journey: adding a fourth FreeBSD edge router at iFog with FogIXP peering, establishing direct BGP sessions with Hetzner, bringing the home network into the AS via an iBGP-speaking MikroTik, and a little traffic engineering to steer Deutsche Telekom traffic over Vultr.

Sat 21 March 2026
Networking

Running Your Own AS: Joining an IXP with a Third Edge Router

Connecting AS201379 to LocIX Düsseldorf via a dedicated edge router - adding direct exchange point peering to the existing multi-homed BGP setup, completing a three-router FreeBSD infrastructure with transit, native peering, and IXP connectivity.

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