Cabletron Systems SMARTSWITCH ROUTER 9032578-05 - Manual (Page 182)

Chapter 12: BGP Configuration Guide
156 SmartSwitch Router User Reference Manual
Routers SSR4 and SSR6 inform router C1 about network 172.16.200.0/24 through External
BGP (EBGP). Router SSR6 announced the route with a MED of 10, whereas router SSR4
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 SSR6, which has a MED
of 10.
Router SSR4 has the following CLI configuration:
Router SSR6 has the following CLI configuration:
EBGP Aggregation Example
Figure 16 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. 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
SSR8
212.19.199.62/24
SSR9
AS-64900
212.19.198.1/24
212.19.192.2/24
194.109.86.6 194.109.86.5