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[ScreenOS] Configuration to deny default route by BGP peer is not working

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Article ID: KB21095 KB Last Updated: 19 Jul 2011Version: 1.0
Summary:
This article describes the procedure used to deny the default route advertised by a BGP peer.
Symptoms:
Environment:
  • Juniper firewall is configured to have BGP neighbors with many devices
  • Customer receives the default route from some peers, and the best default route is selected based on metric.
  • An access list is created with IP 0.0.0.0/0, to deny the default route; but the route is still in the rib-in table.

Configuration:
set protocol bgp 1234
set enable
set neighbor 20.20.20.2 remote-as 4321 local-ip 20.20.20.1/28 outgoing-interface ethernet0/2
set neighbor 20.20.20.2 enable
unset ipv4 synchronization
set ipv4 neighbor 20.20.20.2 activate
set ipv4 neighbor 20.20.20.2 route-map "default-route deny" in
unset ipv6 synchronization
set access-list 1
set access-list 1 deny ip 0.0.0.0/0 1
set route-map name "default-route deny" deny 1
set match ip 1
Solution:
The above configuration above will not block the default route.
This is because the 0.0.0.0/0 in the set access-list 1 deny ip 0.0.0.0/0 1 statement is treated as any IP address, not the default route.
The correct statement  to deny the default route is:
set access-list 1 deny default-route 1
When this access-list is selected in the route-map, it will filter out the default route. 

Note:  You cannot configure the deny default-route statement thru the WebUI.

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