What is used by BGP to guarantee a loop free path to reach a destination?
- a record of each autonomous system that a routing advertisement has traversed
- a distance calculation based on cumulative delay and minimum bandwidth
- the count of router hops to reach a destination
- the cumulative cost as measured in bandwidth
Answers Explanation & Hints:
BGP is a path vector protocol which uses several path attributes to determine the best path. To prevent loops BGP updates include a record of each autonomous system that the routing advertisement traversed. A BGP router that receives the update should not see its own AS in the AS Path. If it did, it would indicate a loop. |