User's Manual

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Users Manual of CS-6306R
45.4.2.1.9 Cancelling BGP-Updated Next Hop Processing
You can cancel the next hop processing for the neighbor's BGP update. The configuration is useful in the
non-broadcast networks such as frame relay or X.25. In frame relay or X.25, BGP neighbors cannot directly
access all other neighbors in the same IP subnet. The following methods can cancel the next hop processing:
 The local IP address that uses the BGP connection replaces the next-hop address of the outgoing route.
 Use the route map to designate the next-hop address of the outgoing route or the incoming route.
Run the following command to cancel the next-hop processing:
Command Purpose
neighbor {ip-address } next-hop-self
Cancels the next-hop processing when BGP neighbors update.
When the previous command is used, the current router notifies itself to take as the next hop of the route.
Therefore, other BGP neighbors will send packets to the current router. It is useful in the non-broadcast
network because a path from the current router to the designated neighbor. However, it is useless in the
broadcast network because unnecessary extra hops will occur.
45.4.2.2 Configuring Senior BGP Characteristics
45.4.2.2.1 Filtering and Modifying Route Update Through Route Map
The route map can be used on each neighbor to filter the route update and modify the parameter’s attributes.
The route map can be applied in both the incoming update and the outgoing update. Only the routes that pass
the route map are processed when the route update is sent or received.
The route map supports that the incoming update and the outgoing update are based on the AS path,
community and network number. The aspath-list command requires be used for the AS matching. The
community matching requires the community-list command. The network matching requires the ip
access-list command .
Run the following command to filter and modify the route update through the route map.
Command Purpose
neighbor {ip-address } route-map
route-map-name {in | out}
Applies the route map to the incoming or outgoing route.
For details, refer to the section “BGP Route Map Example”.
45.4.2.2.2 Configuring Aggregation Addres
The non-type inter-field route can create the aggregation route (and super network) to minimize the routing
table. You can configure the aggregation route by redistributing the aggregation route to BGP or by using the
aggregation attribute described in the following table. If the BGP table has at least one more detailed record,
add the aggregation address to the BGP table.
Use one or several of the following command to create the aggregation address in the routing table:
Command Purpose
aggregate network/len
Creates the aggregation address in the routing table.
aggregate network/len summary-only
Broadcasts only the summary address.
aggregate network/len route-map
map-name
Generates the designated aggregation address through the
route map.