BGP Filtering with Prefix-Lists and Access-List

Deny Prefix 10.0.0.0/22 to be learned from neighbor 24.1.1.2 on R4

R4#
!
router bgp 400
 no synchronization
 bgp log-neighbor-changes
 network 4.4.4.0 mask 255.255.255.0
 neighbor 24.1.1.2 remote-as 123
 neighbor 24.1.1.2 prefix-list DENY-PREFIX in
 neighbor 34.1.1.3 remote-as 123
 no auto-summary
!
ip prefix-list DENY-PREFIX seq 10 deny 10.0.0.0/22
ip prefix-list DENY-PREFIX seq 20 permit 0.0.0.0/0 le 32




On the same note we can filter the BGP routes via Access-list standard and extended
R4#
ip access-list standard BLOCK_10
deny 10.0.0.0 0.0.0.255
permit any
!
router bgp 200
neighbor 192.10.1.254 distribute-list BLOCK_10 in