Cisco ASR 9000 Series Configuration Guide

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.
The following example shows how to configure a route policy where the in operator evaluates to true if one
or more of the regular expression matches in the set my-as-set successfully match the AS path associated with
the route. If it is a match, then the clear command clears the associated flap statistics.
as-path-set my-as-set
ios-regex '_12$',
ios-regex '_13$'
end-set
route-policy policy_a
if as-path in my-as-set then
pass
else
drop
endif
end-policy
clear bgp ipv4 unicast flap-statistics route-policy policy_a
Debug
The debug attach point provides increased control based on prefix-based match operations. This attach point
is typically used to filter debug output for various BGP commands based on the prefix of the route.
The following example shows how to configure a route policy that will only pass the prefix 20.0.0.0 with
prefix length 8; therefore, the debug output shows up only for that prefix.
route-policy policy_b
if destination in (10.0.0.0/8) then
pass
else
drop
endif
end-policy
debug bgp update policy_b
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.1.x
500 OL-30423-03
Implementing Routing Policy
Attach Points

Cisco ASR 9000 Series Specifications

General

Series	ASR 9000
Category	Network Router
Modular Design	Yes
Redundancy	Yes (Hardware and Software)
Operating System	Cisco IOS XR
Interfaces/Ports	10G, 40G, 100G, 400G Ethernet
Expansion Slots	Varies by model
Routing Protocol	BGP, OSPF, IS-IS, EIGRP
Management	CLI, SNMP, NETCONF
Power Supply	Redundant
Port Density	Varies by model
Power Supply Options	AC, DC
Memory	Varies by model
Storage	Varies by model
Dimensions	Varies by model
Weight	Varies by model