BGP Multihoming 2 ISP Berbeda

konfigurasi IP Address dan routing EIGRP masih tetap sama dengan yang lab
sebelumnya, hanya saja BGP AS 23 di rubah menjadi BGP AS 2 di R2 dan BGP AS 3
di R3

Konfigurasi BGP di Router 1

router bgp 1
 bgp log-neighbor-changes
 network 1.1.1.1 mask 255.255.255.255
 network 11.11.11.11 mask 255.255.255.255
 neighbor 12.12.12.2 remote-as 2
 neighbor 12.12.12.2 next-hop-self
 neighbor 13.13.13.3 remote-as 3
 neighbor 13.13.13.3 next-hop-self
!       


Konfigurasi BGP di R2

router bgp 2
 bgp log-neighbor-changes
 network 22.22.22.22 mask 255.255.255.255
 neighbor 12.12.12.1 remote-as 1
 neighbor 12.12.12.1 next-hop-self
 neighbor 23.23.23.3 remote-as 3
 neighbor 23.23.23.3 next-hop-self
 neighbor 24.24.24.4 remote-as 4
 neighbor 24.24.24.4 next-hop-self
!       


Konfigurasi BGP di R3

router bgp 3
 bgp log-neighbor-changes
 network 33.33.33.33 mask 255.255.255.255
 neighbor 13.13.13.1 remote-as 1
 neighbor 13.13.13.1 next-hop-self
 neighbor 23.23.23.2 remote-as 2
 neighbor 23.23.23.2 next-hop-self
 neighbor 34.34.34.4 remote-as 4
 neighbor 34.34.34.4 next-hop-self
!     


Konfigurasi BGP di R4

router bgp 4
 bgp log-neighbor-changes
 network 44.44.44.44 mask 255.255.255.255
 neighbor 24.24.24.2 remote-as 2
 neighbor 24.24.24.2 next-hop-self
 neighbor 34.34.34.3 remote-as 3
 neighbor 34.34.34.3 next-hop-self
!   


setelah di pastikan semua bgp  terhbung

R1(config)#do sh ip bgp
BGP table version is 6, local router ID is 11.11.11.11
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>  11.11.11.11/32   0.0.0.0                  0         32768 i
 *>  22.22.22.22/32   12.12.12.2               0             0 2 i
 *                    13.13.13.3                             0 3 2 i
 *   33.33.33.33/32   12.12.12.2                             0 2 3 i
 *>                   13.13.13.3               0             0 3 i
 *   44.44.44.44/32   13.13.13.3                             0 3 4 i
 *>                   12.12.12.2                             0 2 4 i



Selanjutnya konfigurasi Load balance agar jalur menuju R2 dan R3 dapat sharing
trafik

Konfigurasi di BGP

router bgp 1
maximum-paths 2
!

Meskipun sudah load balance agar kedua jalur bisa digunakan secara bersamaan
tetap saja bgp hanya memilih satu jalur saja, kalau di lab sebelum menggunakan
ISP yang sama jadi ketika di load balance akan otomatis sharing trafik,
karena itu menggunakna beda ISP beda AS nya juga, oleh karena itu perlu
di tambahkan perintah berikut :

router bgp 1
bgp bestpath as-path multipath-relax
!


verifikasi di R1

R1#sh ip bgp
BGP table version is 6, local router ID is 11.11.11.11
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>  1.1.1.1/32       0.0.0.0                  0         32768 i
 *>  11.11.11.11/32   0.0.0.0                  0         32768 i
 *>  22.22.22.22/32   12.12.12.2               0             0 2 i
 *                    13.13.13.3                             0 3 2 i
 *   33.33.33.33/32   12.12.12.2                             0 2 3 i
 *>                   13.13.13.3               0             0 3 i
 *>  44.44.44.44/32   12.12.12.2                             0 2 4 i
 *m                   13.13.13.3                             0 3 4 i
R1#sh ip route  44.44.44.44
Routing entry for 44.44.44.44/32
  Known via "bgp 1", distance 20, metric 0
  Tag 2, type external
  Last update from 13.13.13.3 00:00:26 ago
  Routing Descriptor Blocks:
    13.13.13.3, from 13.13.13.3, 00:00:26 ago
      Route metric is 0, traffic share count is 1
      AS Hops 2
      Route tag 2
      MPLS label: none
  * 12.12.12.2, from 12.12.12.2, 00:00:26 ago
      Route metric is 0, traffic share count is 1
      AS Hops 2
      Route tag 2
      MPLS label: none

R1#trace 44.44.44.44     
Type escape sequence to abort.
Tracing the route to 44.44.44.44
VRF info: (vrf in name/id, vrf out name/id)
  1 12.12.12.2 12 msec
    13.13.13.3 10 msec
    12.12.12.2 9 msec
  2 34.34.34.4 18 msec
    24.24.24.4 18 msec
    34.34.34.4 17 msec


Terlihat di atas proses load balance dengan berbeda ISP dapat berjalan dengan
baik, namun pada kecepatan bandwith yang sama, beda hal lagi apabila kedua
jalur R2 dan R3 berbeda bandwithnya tentu akan menimbulkan masalah, oleh karena
itu perlu adanya load balance bandwith pada link yang berbeda

Setting Bandwith di masing masing jalur

R1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#int s2/0
R1(config-if)#set ban
R1(config-if)#set band
R1(config-if)#ban   
R1(config-if)#bandwidth 100
R1(config-if)#int s2/1
R1(config-if)#ban
R1(config-if)#bandwidth 200
R1(config-if)#exit
R1(config)#exit


Kemudian konfigurasi BGP dmzlink-bw yang berfungsi untu load balance bandwith

R1(config)#router bgp 1
R1(config-router)#bgp dmzlink-bw
R1(config-router)#neighbor 12.12.12.2 dm
R1(config-router)#neighbor 12.12.12.2 dmzlink-bw
R1(config-router)#neighbor 13.13.13.3 dmzlink-bw
R1(config-router)#do clear ip bgp *


Verifikasi sh ip bgp di R1

R1#sh ip bgp
BGP table version is 6, local router ID is 11.11.11.11
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>  1.1.1.1/32       0.0.0.0                  0         32768 i
 *>  11.11.11.11/32   0.0.0.0                  0         32768 i
 *>  22.22.22.22/32   12.12.12.2               0             0 2 i
 *                    13.13.13.3                             0 3 2 i
 *   33.33.33.33/32   12.12.12.2                             0 2 3 i
 *>                   13.13.13.3               0             0 3 i
 *>  44.44.44.44/32   12.12.12.2                             0 2 4 i
 *m                   13.13.13.3                             0 3 4 i


Verifikasi menggunakan trace dari R1 ke R4

R1(config-router)#do sh ip route 44.44.44.44
Routing entry for 44.44.44.44/32
  Known via "bgp 1", distance 20, metric 0
  Tag 2, type external
  Last update from 13.13.13.3 00:00:41 ago
  Routing Descriptor Blocks:
    13.13.13.3, from 13.13.13.3, 00:00:41 ago
      Route metric is 0, traffic share count is 48
      AS Hops 2
      Route tag 2
      MPLS label: none
  * 12.12.12.2, from 12.12.12.2, 00:00:41 ago
      Route metric is 0, traffic share count is 23
      AS Hops 2
      Route tag 2
      MPLS label: none


Alhamdulillah load balance di R1 dan R3 berjalan dengan baik, share count nya
saling menyesuaikan dengan kapasistas bandwitdhnya

Selesei


Salam Ngoprek

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