The Internet’s inter-domain routing infrastructure, provided today by BGP, is extremely rigid and does not facilitate the introduction of new inter-domain routing protocols. This rigidity has made it incredibly difficult to widely deploy critical fixes to BGP. It has also depressed ASes’ ability to sell value-added services or replace BGP entirely with a more sophisticated protocol. Even if operators undertook the significant effort needed to fix or replace BGP, it is likely the next protocol will be just as difficult to change or evolve. To help, this paper identifies two features needed in the routing infrastructure (i.e., within any inter-domain routing protocol) to facilitate evolution to new protocols. To understand their utility, it presents D-BGP, a version of BGP that incorporates them.