This is an outdated draft that was used to review the content with FreeBSD contributors. For the latest revision, vist http://shawndebnath.com/articles/2016/03/27/freebsd-jails-with-vlan-howto.html.
This article discusses how to set up jails on a FreeBSD 11-CURRENT system utilizing VIMAGE (aka VNET) to provide a virtualized independent network stack for each jail with support for VLAN tagging.