BGP ORIGIN attribute manipulation and its impact on the Internet
Curated from Cloudflare Blog
BGP path selection is often treated as a deterministic science, yet operators frequently encounter unexplained routing instability that defies standard best-path algorithms. This analysis reveals that the ORIGIN attribute, traditionally viewed as a simple validity marker, is routinely rewritten by transit providers to manipulate traffic flow. When nearly seventy percent of paths undergo such manipulation, relying on ORIGIN for decision-making introduces significant unpredictability into your network topology. This practice undermines the stability you expect from BGP, potentially causing suboptimal routing or intermittent connectivity issues that are difficult to diagnose using standard tools. As engineers, we must acknowledge that the theoretical model of BGP does not always match the messy reality of global transit peering. To mitigate these risks, you should evaluate your route selection policies to ensure they are robust against attribute manipulation rather than assuming strict adherence to protocol specifications. Focus on more stable metrics like AS path length or local preference when designing your routing strategy to maintain consistent traffic engineering outcomes.
By doing in-depth testing, we found nearly 70% of BGP paths experience ORIGIN attribute rewrites by transit providers seeking traffic advantages. We examine the global impact of this practice and argue for deprecating ORIGIN in route selection.
— Cloudflare Blog