Cisco ASR 9000 Series Configuration Guide

end-set
route-policy inbound-tx
if destination in too-specific or destination in rfc1918 then
drop
endif
set med 1000
set local-preference 90
set community (2:1001) additive
if community matches-any ([101..106]:202) then
prepend as-path 2.30 2
set community (2:666) additive
if med is 666 or med is 225 then
set origin incomplete
else
set origin igp
endif
else
set community (2:999) additive
endif
end-policy
router bgp 2
neighbor 10.0.1.2 address-family ipv4 unicast route-policy inbound-tx in
Modular Inbound Policy: Example
The following policy example shows how to build two inbound policies, in-100 and in-101, for two different
peers. In building the specific policies for those peers, the policy reuses some common blocks of policy that
may be common to multiple peers. It builds a few basic building blocks, the policies common-inbound,
filter-bogons, and set-lpref-prepend.
The filter-bogons building block is a simple policy that filters all undesirable routes, such as those from the
RFC 1918 address space. The policy set-lpref-prepend is a utility policy that can set the local preference and
prepend the AS path according to parameterized values that are passed in. The common-inbound policy uses
these filter-bogons building blocks to build a common block of inbound policy. The common-inbound policy
is used as a building block in the construction of in-100 and in-101 along with the set-lpref-prepend building
block.
This is a simple example that illustrates the modular capabilities of the policy language.
prefix-set bogon
10.0.0.0/8 ge 8 le 32,
0.0.0.0,
0.0.0.0/0 ge 27 le 32,
192.168.0.0/16 ge 16 le 32
end-set
!
route-policy in-100
apply common-inbound
if community matches-any ([100..120]:135) then
apply set-lpref-prepend (100,100,2)
set community (2:1234) additive
else
set local-preference 110
endif
if community matches-any ([100..666]:[100..999]) then
set med 444
set local-preference 200
set community (no-export) additive
endif
end-policy
!
route-policy in-101
apply common-inbound
if community matches-any ([101..200]:201) then
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.1.x
546 OL-30423-03
Implementing Routing Policy
Modular Inbound Policy: Example

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