Administrator Guide
BGP 1341
Inbound Policy
An inbound policy is a policy applied to UPDATE messages received from
peers. Dell Networking BGP supports the following inbound policies which
are matched against incoming route updates in the order below:
• A global prefix filter that applies to all neighbors (
distribute-list in
)
• A per-neighbor AS path filter (
neighbor filter-list in
)
• A prefix filter that applies to a specific neighbor (
neighbor prefix-list in
)
• A per-neighbor route map (
neighbor route-map in
)
These policy mechanisms determine whether to accept or reject routes
received from neighbors. A route map may also change the attributes of
received routes.
Within a route map, match terms are considered in the following order:
•AS path list
•Prefix list
• Community list
When processing list terms, a match for any term indicates a match and
processing stops.
Outbound Policy
An outbound policy is a policy applied to BGP's best routes (those in the local
RIB and active aggregates) and determines which routes are advertised to
each peer. The route map option may also change the attributes advertised to
a peer. Dell Networking BGP supports the following outbound policies which
are matched against outgoing routes in the order below:
• A per-neighbor AS path filter (
neighbor filter-list out
)
• A prefix filter that applies to all neighbors (
distribute-list out
)
• A prefix filter that applies to a specific neighbor (
neighbor prefix-list out
)
• A per-neighbor route map (
neighbor route-map out
)
Within a route map, match terms are considered in the following order:
•AS path list
•Prefix list
• Community list