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SAC121 - SSAC Briefing on Routing Security

Warren Kumari
Tim April
ICANN Security and Stability Advisory Committee (SSAC) Reports and Advisories (2022), pp. 36


Like all other Internet applications, the Domain Name System (DNS) depends on the Internet’s routing system, which controls the data paths across the Internet’s more than 70,000 autonomously managed networks. A longstanding problem with the routing system is that its key protocol, the border gateway protocol (BGP), does not protect against incorrect routing information. BGP was designed in the late 1980’s and early 1990’s when the Internet consisted of only a few hundred networks that all trusted one another. As the Internet grew and the number of networks increased, the number of routing incidents increased and this implicit trustworthiness waned. The routing system today is subject to a continuous stream of routing anomalies that affect its integrity and that sometimes cause large DNS outages. For example, in April of 2018 attackers were able to “hijack” routes to Amazon’s Route53 DNS services, which resulted in DNS traffic for domains hosted on this service ending up at a different destination network where it was served by malicious DNS servers. In this report, the SSAC discusses events like these and what impact similar incidents can have on the DNS, surveys the pros and cons of various solutions, and discusses future security extensions of the routing system (e.g., path validation). The main focus of this report is on the security and stability implications for the DNS, although most of it also applies to other types of Internet applications (e.g., email, web, media streaming). This report provides a tutorial-style discussion accessible to non-technical members of the ICANN community and elsewhere (e.g., policy makers and legal experts). It does not contain any recommendations to the ICANN Board. Because this report is intended to be understandable to a non-technical audience, it sometimes simplifies technical details that are not relevant to the discussion.