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Re: question on BGP aggregation
the ASes in the AS_SET resulted from merging 2 or more AS_PATHS, you only know at least one of them is connected to AS3 ...
more details at rfc4271:
"An AS_SET implies that the destinations listed in the NLRI can be reached through paths that traverse at least some of the constituent autonomous systems. AS_SETs provide sufficient information to avoid routing information looping; however, their use may prune potentially feasible paths because such paths are no longer listed individually in the form of AS_SEQUENCEs. In practice, this is not likely to be a problem because once an IP packet arrives at the edge of a group of autonomous systems, the BGP speaker is likely to have more detailed path information and can distinguish individual paths from destinations. "
On Oct 22, 2008, at 8:17 PM, Kai Chen wrote: