rpsec-4----Page:2
1  2  3  4  5  6 

Path Considerations
The premises of this draft are:
You cannot form policy based on the AS Path transmitted through BGP.
You cannot predict traffic path from the AS Path contained in a BGP update.
Three examples are provided to show why the AS Path actually used by an advertising peer may not be the actual AS Path used to transit traffic.
The information advertised is a subset of the information available in the routing system.
PPT Version