References For Rib; Rib Data Structures In Bgp And Other Protocols; Rib Administrative Distance - Cisco NCS 5500 Series Configuration Manuals

References for RIB

rcc ipv6 unicast period 500
This example shows how to enable Label Consistency Checker (LCC) background scan with a period
of 500 milliseconds between buffers in scans for IPv6 unicast tables:
lcc ipv6 unicast period 500
This example shows how to run Route Consistency Checker (RCC) on-demand scan for subnet
10.10.0.0/16 in vrf1:
show rcc ipv4 unicast 10.10.0.0/16 vrf vrf 1
This example shows how to run Label Consistency Checker (LCC) on-demand scan on all labels for
IPv6 prefixes:
show lcc ipv6 unicast all
References for RIB
This section provides additional conceptual information on RIB. It includes the following topics:
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RIB Data Structures in BGP and Other Protocols

RIB uses processes and maintains data structures distinct from other routing applications, such as Border
Gateway Protocol (BGP) and other unicast routing protocols. However, these routing protocols use internal
data structures similar to what RIB uses, and may internally refer to the data structures as a RIB. For example,
BGP routes are stored in the BGP RIB (BRIB). RIB processes are not responsible for the BRIB, which are
handled by BGP.
The table used by the line cards and RP to forward packets is called the Forwarding Information Base (FIB).
RIB processes do not build the FIBs. Instead, RIB downloads the set of selected best routes to the FIB processes,
by the Bulk Content Downloader (BCDL) process, onto each line card. FIBs are then constructed.

RIB Administrative Distance

Forwarding is done based on the longest prefix match. If you are forwarding a packet destined to 10.0.2.1,
you prefer 10.0.2.0/24 over 10.0.0.0/16 because the mask /24 is longer (and more specific) than a /16. Routes
from different protocols that have the same prefix and length are chosen based on administrative distance.
For instance, the Open Shortest Path First (OSPF) protocol has an administrative distance of 110, and the
Intermediate System-to-Intermediate System (IS-IS) protocol has an administrative distance of 115. If IS-IS
and OSPF both download 10.0.1.0/24 to RIB, RIB would prefer the OSPF route because OSPF has a lower
administrative distance. Administrative distance is used only to choose between multiple routes of the same
length.
Routing Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x
122
RIB Data Structures in BGP and Other Protocols, on page 122
RIB Administrative Distance, on page 122
RIB Statistics, on page 123
RIB Quarantining, on page 124
Route and Label Consistency Checker, on page 124
Implementing and Monitoring RIB