FreeBSD networking in virtualised hosting — 2021 and beyond

Patrick M. Hausen <>

This talk will present the current state of networking for FreeBSD based containers (jails) and virtual machines based on our own experience running a private hosting infrastructure.

I will present the challenges we faced and solved, like IPv4 address scarcity or vastly different network architectures across various bare metal providers. And the ones we are still facing like increasingly large broadcast domains in layer 2 networking, and the ideas we (and others) have about possible solutions and the future direction of the virtual network stack.

This is an operator’s point of view that references the kernel and userland implementation but focuses on the use of the various subsystems involved instead of the kernel implementation proper.

Patrick M. Hausen

Patrick M. Hausen, born 1968, developed an interest in “all things Unix” and networking in general in the late 80’s. Having worked on various commercial implementations and looking for an operating system that would be more capable than Minix for actual daily use at home he found out about FreeBSD in 1993. He’s been using, hacking, advocating and occasionally cursing FreeBSD ever since.