Riverstone Networks WICT1-12 - Manual (Page 291)

Riverstone Networks RS Switch Router User Guide Release 8.0 16-33
BGP Configuration Guide BGP Configuration Examples
Routers R4 and R6 inform router C1 about network 172.16.200.0/24 through External BGP (EBGP). Router R6
announced the route with a MED of 10, whereas router R4 announces the route with a MED of 20. Of the two EBGP
routes, router C1 chooses the one with a smaller MED. Thus router C1 prefers the route from router R6, which has a
MED of 10.
Router R4 has the following CLI configuration:
Router R6 has the following CLI configuration:
16.3.7 EBGP Aggregation Example
Figure 16-9 shows a simple EBGP configuration in which one peer is exporting an aggregated route to its upstream
peer and restricting the advertisement of contributing routes to the same peer. The aggregated route is 212.19.192.0/19.
Figure 16-9 Sample BGP configuration (route aggregation)
bgp create peer-group pg752to751 type external autonomous-system 64751
bgp add peer-host 10.200.12.15 group pg752to751
#
# Set the MED to be announced to peer group pg752to751
#
bgp set peer-group pg752to751 metric-out 20
bgp create peer-group pg752to751 type external autonomous-system 64751
bgp add peer-host 10.200.12.15 group pg752to751
bgp set peer-group pg752to751 metric-out 10
Physical Link
Legend:
Peering Relationship
AS-64901
R 8
212.19.199.62/24
R 9
AS-64900
212.19.198.1/24
212.19.192.2/24
194.109.86.6 194.109.86.5