Next-Hop; Clear-Policy - Cisco ASR 9000 Series Routing Configuration Manual

Attach Points
the upstream neighbor with a permit or deny so that the neighbor can filter updates before sending them on
to their destination.
prefix-set orf-preset
172.16.1.0/24,
172.16.5.0/24,
172.16.11.0/24
end-set
route-policy policy-orf
if orf prefix in orf-preset then
drop
endif
if orf prefix in (172.16.3.0/24, 172.16.7.0/24, 172.16.13.0/24) then
pass
endif
router bgp 2
neighbor 1.1.1.1
remote-as 3
address-family ipv4 unicast
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.
.

Next-hop

The next-hop attach point provides increased control based on protocol and prefix-based match operations.
The attach point is typically used to decide whether to act on a next-hop notification (up or down) event.
Support for next-hop tracking allows BGP to monitor reachability for routes in the Routing Information Base
(RIB) that can directly affect BGP prefixes. The route policy at the BGP next-hop attach point helps limit
notifications delivered to BGP for specific prefixes. The route policy is applied on RIB routes. Typically,
route policies are used in conjunction with next-hop tracking to monitor non-BGP routes.
The following example shows how to configure the BGP next-hop tracking feature using a route policy to
monitor static or connected routes with the prefix 10.0.0.0 and prefix length 8.
route-policy nxthp_policy_A
if destination in (10.0.0.0/8) and protocol in (static, connected) then
pass
endif
end-policy
router bgp 2
address-family ipv4 unicast
nexthop route-policy nxthp_policy_A

Clear-Policy

The clear-policy attach point provides increased control based on various AS path match operations when
using a clear bgp command. This attach point is typically used to decide whether to clear BGP flap statistics
based on AS-path-based match operations.
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
576
orf route-policy policy-orf
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Implementing Routing Policy