BGP basic documentation 2

forming adjacencies using loopback. (eBGP)


advantages: 
- dapat terhubung secara logical. ( ga perlu directly connected ).
- loopback ga bisa down, kecuali memang disengaja secara config ( klo port bisa sewaktu2 down ).


disadvantages:
- agak ribet konfigurasi.
- butuh command ebgp-multihop ( pada address yang ga ada di subnet yang sama )
- butuh command update-source loopback
- butuh route kearah loopback address!!


==================
R1
router bgp 100
neighbor 3.3.3.3 remote-as 200




R3
router bgp 200
neighbor 1.1.1.1 remote-as 100

#show ip bgp summary    !! bagian up/downnya never.

^ solusi: harus ditambahkan command multihop

R1
conf t
# router bgp 100
# neighbor 3.3.3.3 ebgp-multihop 2  !! jumlah maksimum hop. bs smp 255. tp sebaiknya sekecil mungkin.
# neighbor 3.3.3.3 update-source loopback0

# ip route 3.3.3.3 255.255.255.255 172.12.123.3



R3
conf t
# router bgp 200
# neighbor 1.1.1.1 ebgp-multihop 2
# neighbor 3.3.3.3 update-source loopback0

# ip route 1.1.1.1 255.255.255.255 172.12.123.1

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