Enhanced AS-Loop Detection for BGP

Misconfiguration and malicious manipulation of BGP AS_Path may lead to route hijack. This document proposes to enhance the BGP [RFC4271] Inbound/ Outbound route processing in the case of detecting an AS loop. It is an enhancement to the current BGP's Inbound/Outbound processing and can be implemented directly on the device, and this document also proposes a centralized usecase. This could empower networks to quickly and accurately figure out they're being victimized. Two options are proposed for the enhancement, a) a local check at the device; b) data collection/analysis at the remote network controller/ server. Both approaches are beneficial for route hijack detection.