Improving the agility of BGP routing

Wirtgen, Thomas [UCL]

The Border Gateway Protocol (BGP) is the key protocol for interconnecting networks on the Internet, enabling its basic functionality. Its origins date back to the early days of the Internet, in 1989. In the following decades, the Internet has evolved significantly and is now an integral part of economic and social life. However, the design of the BGP protocol no longer meets modern needs. Although efforts to enhance the protocol over time, certain elements of its design are resistant to change, due to its critical role in the Internet infrastructure. This thesis aims to redesign BGP routing by focusing on three key aspects of modern routing protocols. First, it explores the possibility of allowing network operators to update their routers, freeing them from vendor constraints that inhibit protocol innovation. By introducing the eBPF virtual machine into BGP implementations, network operators gain the ability to design custom features without relying on the IETF or router vendors. Second, the thesis deals with the modernization of BGP message transport. While the TCP protocol was once sufficient to ensure reliable transmission of routing messages, it now suffers from a number of limitations including its lack of security features. Since 2021, a new transport protocol called QUIC has been standardized by the IETF. QUIC combines new features like connection migration and stream multiplexing with the security features of TLS and the reliability of TCP. The thesis demonstrates the advantages of using QUIC and its characteristics for routing protocols. The third and final part focuses on improving the security of BGP routing. By default, BGP assumes that advertised routes are usable and accessible in the data plane without verification, which is often a false assumption. To overcome this problem, we propose a system to validate and ensure the reachability of BGP-learned routes in the data plane.