Neighbours, advertised prefixes and the guards that keep a session from becoming an incident.
One prefix per line.
! Cisco IOS / IOS-XE — BGP AS 65001, generated by NetField
! Every eBGP neighbour should have an inbound and outbound policy — a missing one is how route leaks happen.
! maximum-prefix protects against a neighbour sending a full table by mistake.
configure terminal
!
router bgp 65001
bgp router-id 10.255.0.1
bgp log-neighbor-changes
! ISP-A transit
neighbor 192.0.2.1 remote-as 64500
neighbor 192.0.2.1 description ISP-A transit
neighbor 192.0.2.1 maximum-prefix 1000 80 restart 15
! ISP-B transit
neighbor 198.51.100.1 remote-as 64501
neighbor 198.51.100.1 description ISP-B transit
neighbor 198.51.100.1 maximum-prefix 1000 80 restart 15
!
address-family ipv4 unicast
network 10.20.0.0 mask 255.255.0.0
neighbor 192.0.2.1 activate
neighbor 192.0.2.1 route-map ISP-A-IN in
neighbor 192.0.2.1 route-map ISP-A-OUT out
neighbor 198.51.100.1 activate
neighbor 198.51.100.1 route-map ISP-B-IN in
neighbor 198.51.100.1 route-map ISP-B-OUT out
exit-address-family
!
end