Information Technology Reference
In-Depth Information
Final Configurations
So far in this case study, you have focused on defining traffic policy. In this section, you
learn the route filtering required to prevent acceptance of Martian address space and to pre-
vent the enterprise from providing transit service. To provide a complete scenario, the route
filtering will be added to the final configurations. The Martian prefix filters are shown in
Example 6-12. The prefix filters for Class D and Class E have been condensed into a single
rule. In an actual deployment, this route filtering would be part of the initial configuration.
The final configurations are shown in Examples 6-13, 6-14, and 6-15.
Example 6-12
Martian Prefix Filtering
Router#show running-config
|
begin prefix
ip prefix-list MARTIAN seq 5 deny 0.0.0.0/8 le 32
ip prefix-list MARTIAN seq 10 deny 10.0.0.0/8 le 32
ip prefix-list MARTIAN seq 15 deny 172.16.0.0/12 le 32
ip prefix-list MARTIAN seq 20 deny 192.168.0.0/16 le 32
ip prefix-list MARTIAN seq 25 deny 127.0.0.0/8 le 32
ip prefix-list MARTIAN seq 30 deny 169.254.0.0/16 le 32
ip prefix-list MARTIAN seq 35 deny 192.0.2.0/24 le 32
ip prefix-list MARTIAN seq 40 deny 224.0.0.0/3 le 32
ip prefix-list MARTIAN seq 50 deny 172.160.0.0/16 le 32
ip prefix-list MARTIAN seq 55 permit 0.0.0.0/0 le 32
!
Example 6-13
Final Configuration for R1
R1#show running-config | begin bgp
router bgp 300
no synchronization
bgp log-neighbor-changes
network 172.160.0.0
neighbor 172.160.1.2 remote-as 300
neighbor 172.160.1.2 update-source loopback0
neighbor 172.160.1.3 remote-as 300
neighbor 172.160.1.3 update-source loopback0
neighbor 100.100.100.1 remote-as 100
neighbor 100.100.100.1 route-map LPREF_IN in
neighbor 100.100.100.1 prefix-list MARTIAN in
neighbor 100.100.100.1 filter-list 10 out
neighbor 100.100.100.1 prefix-list PFX_OUT out
no auto-summary
!
route-map LPREF_IN permit 10
set local-preference 120
!
ip as-path access-list 10 permit ^$
!
ip prefix-list PFX_OUT seq 5 permit 172.160.0.0/16
ip prefix-list PFX_OUT seq 10 deny any
