Information Technology Reference
In-Depth Information
Example 9-14
Final Customer Aggregation Edge Router BGP Configuration (Continued)
ip prefix-list GTLDSERVERS seq 45 permit 192.43.172.0/24
ip prefix-list GTLDSERVERS seq 50 permit 192.48.79.0/24
ip prefix-list GTLDSERVERS seq 55 permit 192.52.178.0/24
ip prefix-list GTLDSERVERS seq 60 permit 192.41.162.0/24
ip prefix-list GTLDSERVERS seq 65 permit 192.55.83.0/24
!
! Prefixes Longer than a /24
ip prefix-list LONG_DAMP seq 5 0.0.0.0/0 ge 24
! Prefixes that are a /22 or /23
ip prefix-list MEDIUM_DAMP seq 5 0.0.0.0/0 ge 22 le 23
! Prefixes that are a /21 or shorter
ip prefix-list SHORT_DAMP seq 5 0.0.0.0/0 le 21
!
A configuration example for a border or peering router is shown in Example 9-15.
Example 9-15
Peering Router Sample BGP Configuration
router bgp 100
no auto-summary
no synchronization
bgp dampening route-map graded-dampening
no bgp fast-external-fallover
bgp log-neighbor-changes
bgp router-id <BGP Router ID>
table-map QOS_Policy
!
neighbor AGG_UPLINK peer-group
neighbor AGG_UPLINK description iBGP Session to Aggregation Routers
neighbor AGG_UPLINK version 4
neighbor AGG_UPLINK password <iBGP Password>
neighbor AGG_UPLINK update-source loopback0
neighbor AGG_UPLINK next-hop-self
neighbor AGG_UPLINK remote-as 100
!
neighbor <Peer Address> description Generic Peering Example to AS1000
neighbor <Peer Address> version 4
neighbor <Peer Address> password <Peer Password>
neighbor <Peer Address> route-map peer_outbound_AS1000 out
neighbor <Peer Address> prefix-list PEER_FILTER in
neighbor <Peer Address> remote-as 1000
...
!
route-map graded-dampening deny 10
match ip address prefix-list ROOTSERVERS
!
route-map graded-dampening deny 20
match ip address prefix-list GTLDSERVERS
continues
