Internet broken for ASN32 speakers today

A BGP vulnerability emerged when an autonomous system network (AS196629) announced a routing update that triggered unexpected behaviour in OpenBGPd. The update contained a path attribute that violated the specifications of RFC4893, a technical standard governing four-byte autonomous system numbers.

When routers receive network updates, they rely on defined protocols to ensure coherent global routing. In this case, BGP updates contained CONFED_SET (confederation) autonomous system paths within the AS4_PATH attribute—a configuration explicitly forbidden by RFC4893. The result was disruptive: routing sessions summarily terminated, interrupting network connectivity.

The technical minutiae reveals a broader systemic risk. While the current impact remains limited, the incident portends more significant disruptions as network implementations become increasingly sophisticated. The potential for widespread network isolation looms should similar protocol breaches become more frequent.

Instead of terminating the session when such errors are encountered, network engineers require configurable options to handle such violations: e.g. rejecting problematic routes while maintaining network session integrity, logging infractions, or implementing graduated response mechanisms.

The incident underscores a fundamental truth of networked systems: complexity is the enemy of reliability. Each layer of technical specification represents both a solution and a potential point of failure.

Investigations are ongoing, with the network's technical team working to isolate the specific implementation that originated the non-compliant routing update. Their findings will be crucial in preventing similar incidents and refining the robustness of global internet routing infrastructure.