OpenBSD has supported routing domains (aka VRF-lite) since 4.6, released in 2009. In 2014, OpenBSD 5.5 gained support for IPv6 routing domains. At its most basic, routing domains are simply multiple routing tables in the same kernel. While seeming like a simple task, there are many gotchas involved in using routing domains in a production network. This talk will give a brief history, as well as some scenarios for why and how you would use routing domains, while describing several of the issues that came up during the initial deployments. Routing domains allows (for example) an airport to radically simplify their physical network configuration, saving costs and configuration overhead. A small demonstration network will be used to illustrate common and uncommon use cases.