Di Posting Oleh : Simple Learning
Kategori : BGP Core Technologies Routing
Prerequisites: CCNP level skills.
Topology
Pic. 1 - Topology Diagram.
Icons designed by: Andrzej Szoblik - http://www.newo.pl
Task 1
On R4 check what prefixes are originated by AS 50.
Task 2
On R4 filter out the following:
- Class A prefixes shorter than /24
- Class C prefixes longer than /27
Task 1
On R4 check what prefixes are originated by AS 50.
The command to use: show ip bgp regexp _50$
Pic. 2 - BGP Table on R4
(prefixes originated by AS 50)
On R4 filter out the following:
- Class A prefixes shorter than /24
- Class C prefixes longer than /27
The following should be filtered out:
Class A prefixes shorter than /24 = 5.5.0.0/16
Class C prefixes longer than /27 = 200.55.55.0/29
R4 Configuration:
!
ip prefix-list MATCH_TASK_2 seq 5 deny 0.0.0.0/1 le 23
ip prefix-list MATCH_TASK_2 seq 10 deny 192.0.0.0/3 ge 28
ip prefix-list MATCH_TASK_2 seq 15 permit 0.0.0.0/0 le 32
!
ip prefix-list MATCH_TASK_2 seq 10 deny 192.0.0.0/3 ge 28
ip prefix-list MATCH_TASK_2 seq 15 permit 0.0.0.0/0 le 32
!
router bgp 124
no synchronization
bgp router-id 172.16.104.4
bgp log-neighbor-changes
network 172.16.104.0 mask 255.255.255.0
network 172.16.144.0 mask 255.255.255.0
neighbor 10.1.14.1 remote-as 124
neighbor 10.1.14.1 route-reflector-client
neighbor 10.1.14.1 prefix-list MATCH_TASK_2 in
neighbor 10.1.24.2 remote-as 124
neighbor 10.1.24.2 route-reflector-client
neighbor 10.1.24.2 prefix-list MATCH_TASK_2 in
no auto-summary
no synchronization
bgp router-id 172.16.104.4
bgp log-neighbor-changes
network 172.16.104.0 mask 255.255.255.0
network 172.16.144.0 mask 255.255.255.0
neighbor 10.1.14.1 remote-as 124
neighbor 10.1.14.1 route-reflector-client
neighbor 10.1.14.1 prefix-list MATCH_TASK_2 in
neighbor 10.1.24.2 remote-as 124
neighbor 10.1.24.2 route-reflector-client
neighbor 10.1.24.2 prefix-list MATCH_TASK_2 in
no auto-summary
!
Verification:
Pic. 3 - BGP Table on R4
Class A prefixes shorter than /24 = 5.5.0.0/16Class C prefixes longer than /27 = 200.55.55.0/29
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