BGP Oscillation (RFC 3345)

BGP Oscillation (RFC 3345)

• BGP Oscillation is common in the context of MED + RR, because,
• BGP only advertise the best path and hide the full list. 
• Similar to RR, it is also with BGP confederation
• RFC 3345 has a very good depiction of how it happens
• And I converted it to a google slides for a better view
• in RFC, there lists a couple of design options to avoid this kind of churn
• In RFC 7964, advertises all available paths by using ADD-PATH
• Always compare MED even from different AS;
• Don't accept MED
• Utilize other BGP attributes higher in the decision process. (a little risky, because if any prefix leaked w/o higher attribute and tied)
• Assign a high IGP cost to inter-cluster-link