Configuring The Route Distinguisher - Cisco ASR 9000 Series Routing Configuration Manual

Implementing BGP

Configuring the Route Distinguisher

The route distinguisher (RD) makes prefixes unique across multiple VPN routing and forwarding (VRF)
instances.
In the L3VPN multipath same route distinguisher (RD)environment, the determination of whether to install
a prefix in RIB or not is based on the prefix's bestpath. In a rare misconfiguration situation, where the best
pah is not a valid path to be installed in RIB, BGP drops the prefix and does not consider the other paths. The
behavior is different for different RD setup, where the non-best multipath will be installed if the best multipath
is invalid to be installed in RIB.
Perform this task to configure the RD.
SUMMARY STEPS
1. configure
2. router bgp as-number
3. bgp router-id ip-address
4. vrf vrf-name
5. rd { as-number : nn | ip-address : nn | auto }
6. Do one of the following:
DETAILED STEPS
Command or Action
Step 1
configure
Step 2 router bgp as-number
Example:
RP/0/RSP0/CPU0:router(config)# router bgp
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Step 3 bgp router-id ip-address
Example:
RP/0/RSP0/CPU0:router(config-bgp)# bgp
router-id 10.0.0.0
Step 4 vrf vrf-name
Example:
RP/0/RSP0/CPU0:router(config-bgp)# vrf
vrf_pe
Step 5 rd { as-number : nn | ip-address : nn | auto }
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• commit
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
Configuring a VPN Routing and Forwarding Instance in BGP
Purpose
Enters BGP configuration mode allowing you to configure the BGP
routing process.
Configures a fixed router ID for the BGP-speaking router.
Configures a VRF instance.
Configures the route distinguisher.
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