.. _bgp: BGP --- :abbr:`BGP (Border Gateway Protocol) is one of the Exterior Gateway Protocols and the de facto standard interdomain routing protocol. The latest BGP version is 4. BGP-4 is described in :rfc:`1771` and updated by :rfc:`4271`. :rfc:`2858` adds multiprotocol support to BGP. IPv4 ^^^^ A simple eBGP configuration: **Node 1:** .. code-block:: sh set protocols bgp 65534 neighbor 192.168.0.2 ebgp-multihop '2' set protocols bgp 65534 neighbor 192.168.0.2 remote-as '65535' set protocols bgp 65534 neighbor 192.168.0.2 update-source '192.168.0.1' set protocols bgp 65534 address-family ipv4-unicast network '172.16.0.0/16' set protocols bgp 65534 parameters router-id '192.168.0.1' **Node 2:** .. code-block:: sh set protocols bgp 65535 neighbor 192.168.0.1 ebgp-multihop '2' set protocols bgp 65535 neighbor 192.168.0.1 remote-as '65534' set protocols bgp 65535 neighbor 192.168.0.1 update-source '192.168.0.2' set protocols bgp 65535 address-family ipv4-unicast network '172.17.0.0/16' set protocols bgp 65535 parameters router-id '192.168.0.2' Don't forget, the CIDR declared in the network statement MUST **exist in your routing table (dynamic or static), the best way to make sure that is true is creating a static route:** **Node 1:** .. code-block:: sh set protocols static route 172.16.0.0/16 blackhole distance '254' **Node 2:** .. code-block:: sh set protocols static route 172.17.0.0/16 blackhole distance '254' IPv6 ^^^^ A simple BGP configuration via IPv6. **Node 1:** .. code-block:: sh set protocols bgp 65534 neighbor 2001:db8::2 ebgp-multihop '2' set protocols bgp 65534 neighbor 2001:db8::2 remote-as '65535' set protocols bgp 65534 neighbor 2001:db8::2 update-source '2001:db8::1' set protocols bgp 65534 neighbor 2001:db8::2 address-family ipv6-unicast set protocols bgp 65534 address-family ipv6-unicast network '2001:db8:1::/48' set protocols bgp 65534 parameters router-id '10.1.1.1' **Node 2:** .. code-block:: sh set protocols bgp 65535 neighbor 2001:db8::1 ebgp-multihop '2' set protocols bgp 65535 neighbor 2001:db8::1 remote-as '65534' set protocols bgp 65535 neighbor 2001:db8::1 update-source '2001:db8::2' set protocols bgp 65535 neighbor 2001:db8::1 address-family ipv6-unicast set protocols bgp 65535 address-family ipv6-unicast network '2001:db8:2::/48' set protocols bgp 65535 parameters router-id '10.1.1.2' Don't forget, the CIDR declared in the network statement **MUST exist in your routing table (dynamic or static), the best way to make sure that is true is creating a static route:** **Node 1:** .. code-block:: sh set protocols static route6 2001:db8:1::/48 blackhole distance '254' **Node 2:** .. code-block:: sh set protocols static route6 2001:db8:2::/48 blackhole distance '254' Route Filter ^^^^^^^^^^^^ Route filter can be applied using a route-map: **Node1:** .. code-block:: sh set policy prefix-list AS65535-IN rule 10 action 'permit' set policy prefix-list AS65535-IN rule 10 prefix '172.16.0.0/16' set policy prefix-list AS65535-OUT rule 10 action 'deny' set policy prefix-list AS65535-OUT rule 10 prefix '172.16.0.0/16' set policy prefix-list6 AS65535-IN rule 10 action 'permit' set policy prefix-list6 AS65535-IN rule 10 prefix '2001:db8:2::/48' set policy prefix-list6 AS65535-OUT rule 10 action 'deny' set policy prefix-list6 AS65535-OUT rule 10 prefix '2001:db8:2::/48' set policy route-map AS65535-IN rule 10 action 'permit' set policy route-map AS65535-IN rule 10 match ip address prefix-list 'AS65535-IN' set policy route-map AS65535-IN rule 10 match ipv6 address prefix-list 'AS65535-IN' set policy route-map AS65535-IN rule 20 action 'deny' set policy route-map AS65535-OUT rule 10 action 'deny' set policy route-map AS65535-OUT rule 10 match ip address prefix-list 'AS65535-OUT' set policy route-map AS65535-OUT rule 10 match ipv6 address prefix-list 'AS65535-OUT' set policy route-map AS65535-OUT rule 20 action 'permit' set protocols bgp 65534 neighbor 2001:db8::2 route-map export 'AS65535-OUT' set protocols bgp 65534 neighbor 2001:db8::2 route-map import 'AS65535-IN' **Node2:** .. code-block:: sh set policy prefix-list AS65534-IN rule 10 action 'permit' set policy prefix-list AS65534-IN rule 10 prefix '172.17.0.0/16' set policy prefix-list AS65534-OUT rule 10 action 'deny' set policy prefix-list AS65534-OUT rule 10 prefix '172.17.0.0/16' set policy prefix-list6 AS65534-IN rule 10 action 'permit' set policy prefix-list6 AS65534-IN rule 10 prefix '2001:db8:1::/48' set policy prefix-list6 AS65534-OUT rule 10 action 'deny' set policy prefix-list6 AS65534-OUT rule 10 prefix '2001:db8:1::/48' set policy route-map AS65534-IN rule 10 action 'permit' set policy route-map AS65534-IN rule 10 match ip address prefix-list 'AS65534-IN' set policy route-map AS65534-IN rule 10 match ipv6 address prefix-list 'AS65534-IN' set policy route-map AS65534-IN rule 20 action 'deny' set policy route-map AS65534-OUT rule 10 action 'deny' set policy route-map AS65534-OUT rule 10 match ip address prefix-list 'AS65534-OUT' set policy route-map AS65534-OUT rule 10 match ipv6 address prefix-list 'AS65534-OUT' set policy route-map AS65534-OUT rule 20 action 'permit' set protocols bgp 65535 neighbor 2001:db8::1 route-map export 'AS65534-OUT' set protocols bgp 65535 neighbor 2001:db8::1 route-map import 'AS65534-IN' We could expand on this and also deny link local and multicast in the rule 20 action deny.