12.28 Filtering Order

CCNP RS 300-101, Implementing BGP, Uncategorized

Multiple filters can be applied to a neighbor at once, so there is an order of operations which must be understood. It is as follows.

For inbound advertisements received from a BGP neighbor, the router processes the following filter mechanisms in this order before the route reaches the BGP forwarding table.

  1. Route-Map in
  2. Filter-List in
  3. Prefix-List in

On the outbound, this process is reversed.

  1. Prefix-List out
  2. Filter-List out
  3. Route-Map out

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