Get the latest tech news
Crafting endless AS paths in BGP
Combining two features you should not use, it is possible to create a BGP loop that results in an infinitely expanding AS path.
BGP confederation is a technique used to reduce the number of iBGP sessions and improve scalability in large autonomous systems ( AS). Most eBGP rules apply between sub-ASes, except that next-hop, MED, and local preferences remain unchanged. AS override is a feature that allows a router to replace the ASN of a neighbor in the AS path of outgoing BGP routes with its own.
Or read this on Hacker News