Interdomain routing has long been primed for an overhaul. Designed for a previous era and since dragged into today's networks through complex configurations, little progress has been made on aligning interdomain routing capabilities with network operator needs. Yet substantial growth has occurred in tangential areas such as datacenter networking. We believe that the barriers to performing interdomain routing research must be lowered to enable researchers and operators to better understand existing problems and evaluate potential improvements. To this end, we propose a testbed that enables the emulation of autonomous systems and their internal routing domains. The testbed allows these emulated networks to advertise routes and exchange traffic with the real Internet, exposing them to the Internet's complex policies and inconsistencies. Our testbed enables experiments to have complete control over the network topology and glue-logic between routing domains, including choice of IGP protocol, routing engine, and route redistribution. In addition, experiments can exchange routes and traffic with ISPs in multiple peering locations across the Internet, enabling experiments which emulate complex, geographically distributed networks.