Cisco ASR 9000 Series Routing Configuration Guide

2
Prefix X is installed in customer VRF as (RD1:X).
3
Prefix X is advertised to IntraAS-RR11 as (RD1:X, RT1).
4
IntraAS-RR11 advertises X to InterAS-RR1 as (RD1:X, RT1).
5
InterAS-RR1 attaches RT2 to prefix X on the inbound and ACCEPT_OWN community on the outbound
and advertises prefix X to IntraAS-RR31.
6
IntraAS-RR31 advertises X to PE11.
7
PE11 installs X in Service VRF as (RD2:X,RT1, RT2, ACCEPT_OWN).
Remote PE: Handling of Accept Own Routes
Remote PEs (PEs other than the originator PE), performs bestpath calculation among all the comparable
routes. The bestpath algorithm has been modified to prefer an Accept Own path over non-Accept Own path.
The bestpath comparison occurs immediately before the IGP metric comparison. If the remote PE receives
an Accept Own path from route-reflector 1 and a non-Accept Own path from route-reflector 2, and if the paths
are otherwise identical, the Accept Own path is preferred. The import operates on the Accept Own path.
BGP DMZ Link Bandwidth for Unequal Cost Recursive Load Balancing
Border Gateway Protocol demilitarized zone (BGP DMZ) Link Bandwidth for Unequal Cost Recursive Load
Balancing provides support for unequal cost load balancing for recursive prefixes on local node using BGP
DMZ Link Bandwidth. The unequal load balance is achieved by using the dmz-link-bandwidth command
in BGP Neighbor configuration mode and the bandwidth command in Interface configuration mode.
BFD Multihop Support for BGP
Bi-directional Forwarding Detection Multihop (BFD-MH) support is enabled for BGP. BFD Multihop
establishes a BFD session between two addresses that may span multiple network hops. Cisco IOS XR Software
BFD Multihop is based on RFC 5883. For more information on BFD Multihop, refer Cisco ASR 9000 Series
Aggregation Services Router Interface and Hardware Component Configuration Guide and Cisco ASR 9000
Series Aggregation Services Router Interface and Hardware Component Command Reference.
BGP Multi-Instance and Multi-AS
Multiple BGP instances are supported on the router corresponding to a Autonomous System (AS). Each BGP
instance is a separate process running on the same or on a different RP/DRP node. The BGP instances do not
share any prefix table between them. No need for a common adj-rib-in (bRIB) as is the case with distributed
BGP. The BGP instances do not communicate with each other and do not set up peering with each other. Each
individual instance can set up peering with another router independently.
Multi-AS BGP enables configuring each instance of a multi-instance BGP with a different AS number.
Multi-Instance and Multi-AS BGP provides these capabilities:
•
Mechanism to consolidate the services provided by multiple routers using a common routing infrastructure
into a single IOS-XR router.
•
Mechanism to achieve AF isolation by configuring the different AFs in different BGP instances.
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
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Implementing BGP
BGP DMZ Link Bandwidth for Unequal Cost Recursive Load Balancing

Cisco ASR 9000 Series Specifications

General

Brand	Cisco
Model	ASR 9000 Series
Category	Network Router
Language	English