Monitoring AS-SETs and why they matter

What this post added

This post introduces Cloudflare Radar's new feature for monitoring AS-SETs, which are crucial for BGP routing and building route filters. It explains how AS-SETs are used to group related networks, their current trust-based limitations, and the upcoming ASPA standard. The post details how accurate AS-SETs prevent route leaks, highlights AS-SET misuse, and showcases the new Radar feature that provides transparent, public listings of AS-SET information, including inferred ASN, IRR sources, member counts, and AS cone sizes, to help network operators monitor and manage their routing configurations.