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!
router bgp 100
address-family ipv4 unicast
network 10.2.3.4/24 route-policy aigp-policy
redistribute ospf osp1 metric 4 route-policy aigp-policy
!
!
end
VRF Dynamic Route Leaking Configuration: Example
These examples show how to configure VRF dynamic route leaking:
Import Routes from default-VRF to non-default-VRF
vrf vrf_1
address-family ipv6 unicast
import from default-vrf route-policy rpl_dynamic_route_import
!
end
Import Routes from non-default-VRF to default-VRF
vrf vrf_1
address-family ipv6 unicast
export to default-vrf route-policy rpl_dynamic_route_export
!
end
Flow-tag propagation
The flow-tag propagation feature enables you to establish a co-relation between route-policies and user-policies.
Flow-tag propagation using BGP allows user-side traffic-steering based on routing attributes such as, AS
number, prefix lists, community strings and extended communities. Flow-tag is a logical numeric identifier
that is distributed through RIB as one of the routing attribute of FIB entry in the FIB lookup table. A flow-tag
is instantiated using the 'set' operation from RPL and is referenced in the C3PL PBR policy, where it is
associated with actions (policy-rules) against the flow-tag value.
You can use flow-tag propagation to:
• Classify traffic based on destination IP addresses (using the Community number) or based on prefixes
(using Community number or AS number).
• Select a TE-group that matches the cost of the path to reach a service-edge based on customer site service
level agreements (SLA).
• Apply traffic policy (TE-group selection) for specific customers based on SLA with its clients.
• Divert traffic to application or cache server.
Restrictions for Flow-Tag Propagation
Some restrictions are placed with regard to using Quality-of-service Policy Propagation Using Border Gateway
Protocol (QPPB) and flow-tag feature together. These include:
Routing Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
95
Implementing BGP
VRF Dynamic Route Leaking Configuration: Example