Cisco ASR 9000 Series Routing Configuration Guide

if destination in (172.16.1.0/24) then
set extcommunity rt (10:101)
set weight 211
elseif origin is egp then
set local-preference 212
set extcommunity rt (10:101)
endif
set extcommunity rt (10:111222) additive
end-policy
vrf vrf-export
address-family ipv4 unicast
export route-policy bgpvrf-export
.
.
.
'Set' is a valid operator for the 'med' attribute at the bgp export attach point.Note
Allocate-Label
The allocate-label attach point provides increased control based on various attribute match operations. This
attach point is typically used in inter-AS option C to decide whether the label should be allocated or not when
sending updates to the neighbor for the IPv4 labeled unicast address family. The attribute setting actions
supported are for pass and drop.
The following example shows how to configure a route policy that passes the prefix 0.0.0.0 with prefix length
0. Label allocation happens only if prefix 0.0.0.0 exists.
route-policy label_policy
if destination in (0.0.0.0/0) then
pass
endif
end-policy
router bgp 2
vrf vrf1
rd auto
address-family ipv4 unicast
allocate-label route-policy label-policy
.
.
.
Retain Route-Target
The retain route target attach point within BGP allows the specification of match criteria based only on route
target extended community. The attach point is useful at the route reflector (RR) or at the Autonomous System
Boundary Router (ASBR).
Typically, an RR has to retain all IPv4 VPN routes to peer with its PE routers. These PEs might require routers
tagged with different route target IPv4 VPN routes resulting in non-scalable RRs. You can achieve scalability
if you configure an RR to retain routes with a defined set of route target extended communities, and a specific
set of VPNs to service.
Another reason to use this attach point is for an ASBR. ASBRs do not require that VRFs be configured, but
need this configuration to retain the IPv4 VPN prefix information.
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
574
Implementing Routing Policy
Attach Points

Cisco ASR 9000 Series Specifications

General

Brand	Cisco
Model	ASR 9000 Series
Category	Network Router
Language	English