BGP Attribute ( Community LIST )

 LAB 9. BGP Attribute ( Community LIST )

Selain menggunakan teknik sebelumnya, kita juga bisa menggunakan numerik community, terlebih dahulu kita hapus konfig BGP dan EIGRP pada lab sebelumnya.

R1,R4,R3

R1(config)#no router eigrp 10 

R2(config)#no router eigrp 10 R1(config)#no router bgp 12 

R2(config)#no router bgp 12 

R3(config)#no router eigrp 10 R3(config)#no router bgp 3

R4(config)#no router bgp 4

 Konfigurasikan BGP pada semua router

R1

R1(config)#router bgp 1

R1(config-router)#neighbor 12.12.12.2 remote-as 2

R1(config-router)#exit

R2

R2(config)#router bgp 2

R2(config-router)#neighbor 12.12.12.1 remote-as 1

R2(config-router)#neighbor 23.23.23.3 remote-as 3

R2(config-router)#neighbor 24.24.24.4 remote-as 4

R3

R3(config)#router bgp 3

R3(config-router)#neighbor 23.23.23.2 remote-as 2

R4

R4(config)#router bgp 4

R4(config-router)#neighbor 24.24.24.2 remote-as 2

R4(config-router)#network 4.4.4.4 mask 255.255.255.255 R4(config-router)#exit

Kita cek apakah R2 (ISP 2) mendapatkan prefix dari customer (R4)

R2(config)#do sh ip bgp

Network Next Hop Metric LocPrf Weight Path

*> 4.4.4.4/32 24.24.24.4 0 0 4 i

sekarang kita lanjut konfigurasi communitynya.

R2

R2(config)#ip community-list 1 permit 2:24 R2(config)#route-map P

R2(config)#route-map PREPEND permit R2(config-route-map)#match community 1

R2(config-route-map)#set as prepend 2 2 2 2 R2(config-route-map)#exit

R2(config)#route-map PREPEND permit 20

Kemudian kita terapkan ke R3 (ISP3)

R2

R2(config)#router bgp 2

R2(config-router)#neighbor 23.23.23.3 route-map PREPEND out 

R2(config-router)#exit

Kemudian config di bagian customer

R4

R4(config)#ip prefix-list Loopback permit 4.4.4.4/32 

R4(config)#route-map PREPEND_COMMUNITY permit 10

R4(config-route-map)#match ip address prefix-list LOOPBACK 

R4(config-route-map)#set community 2:24R4(config-route-map)#exit

R4(config)#route-map PREPEND_COMMUNITY permit 20 R4(config-route-map)#exit

R4(config)#router bgp 4

R4(config-router)#neighbor 24.24.24.2 route-map PREPEND_COMMUNITY out

R4(config-router)#neighbor 24.24.24.2 send-community R4(config-router)#exit

R4(config)#do clear ip bgp *

Kita verifikasi pada R2

R2

R2(config)#do show ip bgp 4.4.4.4

BGP routing table entry for 4.4.4.4/32, version 7

Paths: (1 available, best #1, table Default-IP-Routing-Table) Flag: 0x820

Advertised to update-groups:

1 2

24.24.24.4 from 24.24.24.4 (4.4.4.4)

Origin IGP, metric 0, localpref 100, valid, external, best

Community: 131096