Quagga: BGP 2 BGP redistribute 2 OSPF

Ada tiga (3) ISP

ISP1:

IP 192.168.1.1/24 menuju ISP3
IP 192.168.3.1/24 menuju ISP2
AS 10
IP 10.100.100.0/24
IP 10.100.200.0/24

ISP3 (kita)

IP 192.168.1.2/24 - menuju ISP1
IP 192.168.2.2/24 - menuju ISP2
AS 30
IP 10.1.1.0/24
IP 10.1.2.0/24 

R4

IP 10.1.1.2/24 menuju ISP3
IP 172.16.1.1  menuju R5
IP 172.16.10.1 LAN
IP 172.16.20.1 LAN

R5

IP 10.1.2.2/24 menuju ISP3
IP 172.16.1.2  menuju R4
IP 172.16.100.1/24 LAN
IP 172.16.200.1/24 LAN

Sambungan Fisik

ISP1 Eth0 -> ISP3 Eth0
ISP1 Eth1 -> ISP2 Eth1
ISP2 Eth0 -> ISP3 Eth1

ISP1 Eth2 10.100.100.1/24
ISP1 Eth3 10.100.200.1/24

ISP2 Eth2 10.10.10.1/24
ISP2 Eth3 10.10.20.1/24

ISP3 Eth2 10.1.1.1/24
ISP3 Eth3 10.1.2.1/24

R4 Eth1/0 -> ISP3 Eth1/2
R5 Eth1/0 -> ISP3 Eth1/3
R4 Eth1/1 -> R5 Eth1/1

Setup connection

ISP1

vtysh
configure terminal
  interface eth0
    ip address 192.168.1.1/24
    no shutdown
    exit
  interface eth1
    ip address 192.168.3.1/24
    no shutdown
    exit
  interface eth2
    ip address 10.100.100.1/24
    no shutdown
    exit
  interface eth3
    ip address 10.100.200.1/24
    no shutdown
    exit
 end

ISP3

vtysh
configure terminal
  interface eth0
    ip address 192.168.1.2/24
    no shutdown
    exit
  interface eth1
    ip address 192.168.2.2/24
    no shutdown
    exit
  interface eth2
    ip address 10.1.1.1/24
    no shutdown
    exit
  interface eth3
    ip address 10.1.2.1/24
    no shutdown
    exit
 end

R4

vtysh
configure terminal
  interface eth0
    ip address 10.1.1.2/24
    no shutdown
    exit
  interface eth1
    ip address 172.16.1.1/24
    no shutdown
    exit
  interface eth2
    ip address 172.16.10.1/24
    no shutdown
    exit
  interface eth3
    ip address 172.16.20.1/24
    no shutdown
    exit
 end

R5

vtysh
configure terminal
  interface eth0
    ip address 10.1.2.2/24
    no shutdown
    exit
  interface eth1
    ip address 172.16.1.2/24
    no shutdown
    exit
  interface eth2
    ip address 172.16.100.1/24
    no shutdown
    exit
  interface eth3
    ip address 172.16.200.1/24
    no shutdown
    exit
 end

BGP Peering

Consider that IP connectivity between ISPs edge routers and Our Core router is already set up and working properly. So we can start to establish BGP peering to both ISPs.

ISP1:

configure terminal
  router bgp 10
  bgp router-id 192.168.1.1
    network 10.100.100.0/24
    network 10.100.200.0/24
    neighbor 192.168.1.2 remote-as 30
  end

Main / Backup Link Setup di ISP3

Lakukan

• accept network kita sendiri
• drop semua tabel IP lainnya, karena kita tidak mau menjadi transit provider
• BGP AS prepend - menaikan AS path ke salah satu ISP (disini ISP1)

ISP3:

configure terminal
  router bgp 30
  bgp router-id 192.168.1.2
    no synchronization
    bgp log-neighbor-changes
    network 10.1.1.0/24
    network 10.1.2.0/24
    neighbor 192.168.1.1 remote-as 10
    !
    ! redistribute routing dari OSPF
    redistribute ospf metric 100 
  end

OSPF

ISP3

configure terminal
 !
 ! area 0 = backbone
 router ospf
 network 10.1.1.0/24 area 0.0.0.0
 network 10.1.2.0/24 area 0.0.0.0
 ! 
 ! redistribute routing dari BGP
 redistribute bgp
 end

R4

configure terminal
 !
 ! area 0 = backbone
 router ospf
 network 10.1.1.0/24 area 0.0.0.0
 network 172.16.1.0/24 area 0.0.0.0
 network 172.16.10.0/24 area 0.0.0.0
 network 172.16.20.0/24 area 0.0.0.0
 end

R5

configure terminal
  !
  ! area 0 = backbone
  router ospf
  network 10.1.2.0/24 area 0.0.0.0
  network 172.16.1.0/24 area 0.0.0.0
  network 172.16.100.0/24 area 0.0.0.0
  network 172.16.200.0/24 area 0.0.0.0
  end

Cek

! perhatikan AS 30 di tambahkan 5x ke routing ke arah AS 10
!
clear ip bgp 10
clear ip bgp 20
show ip bgp
show ip route

show ip route
show ip bgp 10.100.1000.0/24
show ip bgp neighbors 192.168.2.2 advertised-routes
show ip bgp neighbor 192.168.1.1 routes
show bgp ipv4 unicast neighbors 
show bgp ipv4 unicast summary

Referensi

• https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-16/irg-xe-16-book/configuring-a-basic-bgp-network.html
• https://wiki.mikrotik.com/wiki/Manual:Simple_BGP_Multihoming

Pranala Menarik

• TCP/IP: Advanced Routing
• Quagga
• Mikrotik
• Cisco
• Juniper
• BIRD: Routing
• IPv6