Lab 94. BGP Attribute (MED)

Objective : 

• MED : digunakan untuk menentukan trafik kembali/downstream
• Mempelajari konfigurasi atribut MED 

Topologi Lab 

 Konfigurasi R1

!
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface Loopback11
 ip address 11.11.11.11 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.1 255.255.255.0
 duplex auto
 speed auto
!
router ospf 1
 log-adjacency-changes
 network 1.1.1.1 0.0.0.0 area 0
 network 12.12.12.1 0.0.0.0 area 0
!
router bgp 12
 no synchronization
 bgp log-neighbor-changes
 network 11.11.11.11 mask 255.255.255.255
 neighbor 2.2.2.2 remote-as 12
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 5.5.5.5 remote-as 12
 neighbor 5.5.5.5 update-source Loopback0
 no auto-summary
!

Konfigurasi R2

!
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface Loopback22
 ip address 22.22.22.22 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.2 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 25.25.25.2 255.255.255.0
 clock rate 2000000
!
interface FastEthernet0/1
 ip address 23.23.23.2 255.255.255.0
 duplex auto
 speed auto
!
router ospf 1
 log-adjacency-changes
 network 2.2.2.2 0.0.0.0 area 0
 network 12.12.12.2 0.0.0.0 area 0
 network 25.25.25.2 0.0.0.0 area 0
!
router bgp 12
 no synchronization
 bgp log-neighbor-changes
 network 22.22.22.22 mask 255.255.255.255
 neighbor 1.1.1.1 remote-as 12
 neighbor 1.1.1.1 update-source Loopback0
 neighbor 1.1.1.1 next-hop-self
 neighbor 5.5.5.5 remote-as 12
 neighbor 5.5.5.5 update-source Loopback0
 neighbor 5.5.5.5 next-hop-self
 neighbor 23.23.23.3 remote-as 34
 neighbor 23.23.23.3 next-hop-self
 no auto-summary
!

 Konfigurasi R3

 !
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Loopback33
 ip address 33.33.33.33 255.255.255.255
!
interface FastEthernet0/0
 ip address 34.34.34.3 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 36.36.36.3 255.255.255.0
 clock rate 2000000
!
interface FastEthernet0/1
 ip address 23.23.23.3 255.255.255.0
 duplex auto
 speed auto
!
router ospf 1
 log-adjacency-changes
 network 3.3.3.3 0.0.0.0 area 0
 network 34.34.34.3 0.0.0.0 area 0
 network 36.36.36.3 0.0.0.0 area 0
!
router bgp 34
 no synchronization
 bgp log-neighbor-changes
 network 33.33.33.33 mask 255.255.255.255
 neighbor 4.4.4.4 remote-as 34
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self
 neighbor 6.6.6.6 remote-as 34
 neighbor 6.6.6.6 update-source Loopback0
 neighbor 6.6.6.6 next-hop-self
 neighbor 23.23.23.2 remote-as 12
 neighbor 23.23.23.2 next-hop-self
 no auto-summary
!

Konfigurasi R4

 !
interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
interface Loopback44
 ip address 44.44.44.44 255.255.255.255
!
interface FastEthernet0/0
 ip address 34.34.34.4 255.255.255.0
 duplex auto
 speed auto
!
router ospf 1
 log-adjacency-changes
 network 4.4.4.4 0.0.0.0 area 0
 network 34.34.34.4 0.0.0.0 area 0
!
router bgp 34
 no synchronization
 bgp log-neighbor-changes
 network 44.44.44.44 mask 255.255.255.255
 neighbor 3.3.3.3 remote-as 34
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 6.6.6.6 remote-as 34
 neighbor 6.6.6.6 update-source Loopback0
 no auto-summary
!

Konfigurasi R5

!
interface Loopback0
 ip address 5.5.5.5 255.255.255.255
!
interface Loopback55
 ip address 55.55.55.55 255.255.255.255
!
interface FastEthernet0/0
 ip address 56.56.56.5 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 25.25.25.5 255.255.255.0
 clock rate 2000000
!
router ospf 1
 log-adjacency-changes
 network 5.5.5.5 0.0.0.0 area 0
 network 25.25.25.5 0.0.0.0 area 0
!
router bgp 12
 no synchronization
 bgp log-neighbor-changes
 network 55.55.55.55 mask 255.255.255.255
 neighbor 1.1.1.1 remote-as 12
 neighbor 1.1.1.1 update-source Loopback0
 neighbor 1.1.1.1 next-hop-self
 neighbor 2.2.2.2 remote-as 12
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 next-hop-self
 neighbor 56.56.56.6 remote-as 34
 neighbor 56.56.56.6 next-hop-self
 no auto-summary
!

Konfigurasi R6

!
interface Loopback0
 ip address 6.6.6.6 255.255.255.255
!
interface Loopback66
 ip address 66.66.66.66 255.255.255.255
!
interface FastEthernet0/0
 ip address 56.56.56.6 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 36.36.36.6 255.255.255.0
 clock rate 2000000
!
router ospf 1
 log-adjacency-changes
 network 6.6.6.6 0.0.0.0 area 0
 network 36.36.36.6 0.0.0.0 area 0
!
router bgp 34
 no synchronization
 bgp log-neighbor-changes
 network 66.66.66.66 mask 255.255.255.255
 neighbor 3.3.3.3 remote-as 34
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 4.4.4.4 remote-as 34
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self
 neighbor 56.56.56.5 remote-as 12
 neighbor 56.56.56.5 next-hop-self
 no auto-summary
!
 
Verifikasi Lab
 
Traceroute dari R1 menuju R4

Secara default BGP akan memilih rute R1-R2-R3-R4. Agar Rute nya dialihkan menjadi R1-R2-R5-R6-R3-R4 maka tambahkan nilai MED nya. Nilai MED yang terbesar justru yang akan dihindari sebagai rutenya.

 

Trace kembali