Cisco: BGP Dua Link main backup - dengan access list dan routemap
Revision as of 08:54, 1 January 2019 by Onnowpurbo (talk | contribs)
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
ISP2
IP 192.168.2.1/24 - menuju ISP3 IP 192.168.3.2/24 - menuju ISP1 AS 20 IP 10.10.10.0/24 IP 10.10.20.0/24
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
Sambungan Fisik
ISP1
ISP1 Eth1/0 -> ISP3 Eth1/0 ISP1 Eth1/1 -> ISP2 Eth1/1 ISP2 Eth1/0 -> ISP3 Eth1/1 ISP1 Eth1/2 10.100.100.1/24 ISP1 Eth1/3 10.100.200.1/24 ISP2 Eth1/2 10.10.10.1/24 ISP2 Eth1/3 10.10.20.1/24 ISP3 Eth1/2 10.1.1.1/24 ISP3 Eth1/3 10.1.2.1/24
Setup connection
ISP1
enable configure terminal interface Ethernet1/0 ip address 192.168.1.1 255.255.255.0 no shutdown exit interface Ethernet1/1 ip address 192.168.3.1 255.255.255.0 no shutdown exit interface Ethernet1/2 ip address 10.100.100.1 255.255.255.0 no shutdown exit interface Ethernet1/3 ip address 10.100.200.1 255.255.255.0 no shutdown exit end
ISP2
enable configure terminal interface Ethernet1/0 ip address 192.168.2.1 255.255.255.0 no shutdown exit interface Ethernet1/1 ip address 192.168.3.2 255.255.255.0 no shutdown exit interface Ethernet1/2 ip address 10.10.10.1 255.255.255.0 no shutdown exit interface Ethernet1/3 ip address 10.10.20.1 255.255.255.0 no shutdown exit end
ISP3
enable configure terminal interface Ethernet1/0 ip address 192.168.1.2 255.255.255.0 no shutdown exit interface Ethernet1/1 ip address 192.168.2.2 255.255.255.0 no shutdown exit interface Ethernet1/2 ip address 10.1.1.1 255.255.255.0 no shutdown exit interface Ethernet1/3 ip address 10.1.2.1 255.255.255.0 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:
enable configure terminal router bgp 10 bgp router-id 192.168.1.1 ! address-family ipv4 unicast network 10.100.100.0 mask 255.255.255.0 network 10.100.200.0 mask 255.255.255.0 neighbor 192.168.3.2 remote-as 20 neighbor 192.168.1.2 remote-as 30 neighbor 192.168.3.2 activate neighbor 192.168.1.2 activate ! neighbor 192.168.3.2 default-originate ! neighbor 192.168.1.2 default-originate end
ISP2:
enable configure terminal router bgp 20 bgp router-id 192.168.2.1 ! address-family ipv4 unicast network 10.10.10.0 mask 255.255.255.0 network 10.10.20.0 mask 255.255.255.0 neighbor 192.168.3.1 remote-as 10 neighbor 192.168.2.2 remote-as 30 neighbor 192.168.3.1 activate neighbor 192.168.2.2 activate 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:
! set access list - hanya IP yang ada di access yang tabel routing-nya bisa lewat ! configure terminal access-list 3 permit 10.100.100.0 0.0.0.255 ! access-list 3 permit 10.100.200.0 0.0.0.255 ! access-list 3 permit 10.10.10.0 0.0.0.255 ! access-list 3 permit 10.10.20.0 0.0.0.255 end
! definisikan route-map configure terminal route-map NET3 permit 10 match ip address 3 set weight 100 route-map NET3 permit 20 end ! ! route-map NET3 permit 20 - terima routing lainnya, hanya access-list 3 di "set weight 100"
! apply ke neighbor ! configure terminal router bgp 30 neighbor 192.168.1.1 remote-as 10 neighbor 192.168.1.1 route-map NET3 in neighbor 192.168.2.1 remote-as 20 network 10.1.1.0 mask 255.255.255.0 network 10.1.2.0 mask 255.255.255.0 clear ip bgp 10 clear ip bgp 20
Cek
! perhatikan AS 30 di tambahkan 5x ke routing ke arah AS 10 ! clear ip bgp 10 clear ip bgp 20 ! show ip bgp
Network Next Hop Metric LocPrf Weight Path *> 10.1.1.0/24 0.0.0.0 0 32768 i *> 10.1.2.0/24 0.0.0.0 0 32768 i * 10.10.10.0/24 192.168.1.1 0 10 20 i *> 192.168.2.1 0 0 20 i * 10.10.20.0/24 192.168.1.1 0 10 20 i *> 192.168.2.1 0 0 20 i *> 10.100.100.0/24 192.168.1.1 0 100 10 i * 192.168.2.1 0 20 10 i *> 10.100.200.0/24 192.168.1.1 0 0 10 i * 192.168.2.1 0 20 10 i
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
- http://evilrouters.net/2008/11/30/using-weights-to-influence-bgp-routing/
- 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