Routing Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

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Routing Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

Implement and Monitor RIB

Explains how RIB stores best routes from multiple protocols, selects the overall preferred routes by administrative distance, and supports forwarding and monitoring across the system.


Routing Information Base (RIB) is a distributed collection of routing connectivity information that

  • maintains routing information for each router in the network

  • stores the best routes learned from all routing protocols that run on the system, and

  • selects the best overall routes and downloads them to the line cards for packet forwarding.

How RIB selects routes

Each routing protocol selects its own best routes and installs those routes, along with their attributes, in RIB.

Within a routing protocol, route selection depends on the metric that the protocol uses. The protocol then downloads its best routes, including equal-cost routes, to RIB.

RIB stores routes from all routing protocols and selects the best overall route by comparing the administrative distance of each protocol.

How RIB supports forwarding

After RIB selects the best overall routes, it downloads those routes to the line cards for packet forwarding.

The term RIB refers both to the RIB processes and to the collection of route data that RIB contains.

Programmatic configuration support

You can programmatically configure RIB for Border Gateway Protocol (BGP) and retrieve operational data by using the openconfig-rib-bgp.yang OpenConfig data model.