Cisco Systems IOS XR Configuring a Route Reflector for BGP

Implementing BGP on Cisco IOS XR Software

How to Implement BGP on CiscoIOSXR Software

RC-60

Cisco IOS XR Routing Configuration Guide

Configuring a Route Reflector for BGP

Perform this task to configure a route reflector for BGP.

All the neighbors configured with the route-reflector-client command are members of the client group,

and the remaining iBGP peers are members of the nonclient group for the local route reflect or.

Together, a route reflector and its clients form a cluster. A cluster of clients usually has a single rout e

reflector. In such instances, the cluster is identified by the software as the router ID of the route reflector.

To increase redundancy and avoid a single point of failure in the network, a cluster can have more than

one route reflector. If it does, all route reflectors in the cluster must be configured with the same 4-byte

cluster ID so that a route reflector can recognize update s from route reflectors in the same cluster. The

bgp cluster-id command is used to configure the cluster ID when the cluster has more than one route

reflector.

SUMMARY STEPS

1. configure

2. router bgp autonomous-system-number

3. bgp cluster-id cluster-id

4. neighbor ip-address

5. remote-as autonomous-system-number

6. address-family {ipv4 unicast | ipv4 multicast | ipv6 unicast | ipv6 multicast}

7. route-reflector-client

8. end

or

commit

DETAILED STEPS

Command or Action Purpose

Step1 configure

Example:

RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step2 router bgp

autonomous-system-number

Example:

RP/0/RP0/CPU0:router(config)# router bgp 120

Enters BGP configuration mode allowing you to configure

the BGP routing process.

Step3 bgp cluster-id

cluster-id

Example:

RP/0/RP0/CPU0:router(config-bgp)# bgp

cluster-id 192.168.70.1

Configures the local router as one of the route refle ctors

serving the cluster. It is configured with the cluster ID of

192.168.70.1 to identify the cluster.

Contents

Main Cisco IOS XR Routing Configuration Guide Page CONTENTS Page Page Page Page Page Page Page Preface Document Revision History Obtaining Documentation Cisco.com Product Documentation DVD Ordering Documentation Documentation Feedback Cisco Product Security Overview Reporting Security Problems in Cisco Products Obtaining Technical Assistance Cisco Technical Support & Documentation Website Submitting a Service Request Definitions of Service Request Severity Obtaining Additional Publications and Information Page Implementing BGP on Cisco IOS XR Software Prerequisites for Implementing BGP on Cisco IOS XR Software Information About Implementing BGP on Cisco IOS XR Software BGP Functional Overview BGP Router Identifier BGP Default Limits BGP Validation of Local Next-Hop Addresses BGP Configuration Configuration Modes Router Configuration Mode Global Address Family Configuration Mode Neighbor Submode Configuration Templates Template Inheritance Rules Page RC-9 RC-10 4. Otherwise, the default value is used. In the example that foll ows, neighbor 10.0.101.5 has the Template Inheritance show bgp neighbors show bgp af-group show bgp session-group show bgp neighbor-group No Default Address Family Routing Policy Enforcement RC-17 Table Policy Update Groups BGP Update Generation and Update Groups BGP Update Group BGP Best Path Algorithm Comparing Pairs of Paths Order of Comparisons Best Path Change Suppression Multiprotocol BGP Page Route Dampening Minimizing Flapping BGP Routing Domain Confederation BGP Route Reflectors Page Page Default Address Family for show Commands How to Implement BGP on Cisco IOS XR Software Enabling BGP Routing Page Page Configuring a Routing Domain Confederation for BGP Page Resetting eBGP Session Immediately Upon Link Failure Logging Neighbor Changes Adjusting BGP Timers Changing the BGP Default Local Preference Value Configuring the MED Metric for BGP Page Configuring BGP Weights Tuning the BGP Best Path Calculation Page Indicating BGP Backdoor Routes Page Configuring Aggregate Addresses Redistributing iBGP Routes into IGP Page Redistributing Prefixes into Multiprotocol BGP Page Configuring BGP Route Dampening Page RC-50 Command or Action Purpose Step6 Clears BGP flap statistics for all routes. /prefix-length Page Applying Policy When Updating the Routing Table Setting BGP Administrative Distance Page Configuring a BGP Neighbor Group Page Page Configuring a BGP Neighbor Page Configuring a Route Reflector for BGP Page Configuring BGP Route Filtering by Route Policy Page Disabling Next Hop Processing on BGP Updates Configuring BGP Community and Extended-Community Filtering Page Configuring Software to Store Updates from a Neighbor Page Disabling a BGP Neighbor Page Resetting Neighbors Using BGP Dynamic Inbound Soft Reset Resetting Neighbors Using BGP Outbound Soft Reset Resetting Neighbors Using BGP Hard Reset Clearing Caches, Tables and Databases Displaying System and Network Statistics Page Monitoring BGP Update Groups RC-76 Configuration Examples for Implementing BGP on Cisco IOS XR This section provides the following configuration examples: Enabling BGP: Example The following shows how to enable BGP. RC-77 Displaying BGP Update Groups: Example The following is sample output from the show bgp update-group command executed in EXEC mode: BGP Neighbor Configuration: Example BGP Confederation: Example BGP Route Reflector: Example Page Page Page Implementing IS-IS on Cisco IOS XR Software Prerequisites for Implementing IS-IS on Cisco IOS XR Software Restrictions for Implementing IS-IS on Cisco IOS XR Software Information About Implementing IS-IS on Cisco IOS XR Software IS-IS Functional Overview Key Features Supported in the Cisco IOS XR IS-IS Implementation IS-IS Configuration Grouping IS-IS Interfaces Multitopology Configuration IPv6 Routing and Configuring IPv6 Addressing Limit LSP Flooding Flood Blocking on Specific Interfaces Maximum LSP Lifetime and Refresh Interval Overload Bit Configuration During Multitopology Operation Single-Topology IPv6 Support Multitopology IPv6 Support Nonstop Forwarding Multi-Instance IS-IS Multiprotocol Label Switching Traffic Engineering Overload Bit on Router Default Routes Attached Bit on an IS-IS Instance Multicast-Intact Feature How to Implement IS-IS on Cisco IOS XR Software Enabling IS-IS and Configuring Level 1 or Level 2 Routing Page Configuring Single Topology for IS-IS Page Page Page Page Configuring Multitopology for IS-IS Page Page Page Controlling LSP Flooding for IS-IS Page Page Page Configuring Nonstop Forwarding for IS-IS Page Configuring Authentication for IS-IS Page Configuring MPLS Traffic Engineering for IS-IS Prerequisite Page Page Tuning Adjacencies for IS-IS on Point-to-Point Interfaces Page Page Setting SPF Interval for a Single-Topology IPv4 and IPv6 Configuration Page Enabling Multicast-Intact for IS-IS Customizing Routes for IS-IS Page Page Configuration Examples for Implementing IS-IS on Cisco IOS XR Configuring Single-Topology IS-IS for IPv6: Example RC-123 Configuring Multitopology IS-IS for IPv6: Example Redistributing IS-IS Routes Between Multiple Instances: Example Page Page Page Implementing OSPF on Cisco IOS XR Software Prerequisites for Implementing OSPF on Cisco IOS XR Software Information About Implementing OSPF on Cisco IOS XR OSPF Functional Overview Key Features Supported in the Cisco IOS XR OSPF Implementation Comparison of Cisco IOS XR OSPFv3 and OSPFv2 Importing Addresses into OSPFv3 OSPF Hierarchical CLI and CLI Inheritance OSPF Routing Components Autonomous Systems Areas Backbone Area Stub Area Not-so-Stubby Area (NSSA) Routers OSPF Process and Router ID Supported OSPF Network Types Route Authentication Methods for OSPF Version 2 Plain Text Authentication MD5 Authentication Authentication Strategies Neighbors and Adjacency for OSPF Designated Router (DR) for OSPF Default Route for OSPF Link-State Advertisement Types for OSPF Version 2 Link-State Advertisement Types for OSPFv3 Virtual Link and Transit Area for OSPF Route Redistribution for OSPF OSPF Shortest Path First Throttling Nonstop Forwarding for OSPF Version 2 Load Balancing in OSPF Version 2 and OSPFv3 Graceful Restart for OSPFv3 Modes of Graceful Restart Operation Restart Mode Helper Mode Graceful Restart Requirements and Restrictions Multicast-Intact Feature How to Implement OSPF on Cisco IOS XR Software Enabling OSPF Page Configuring Stub and Not-so-Stubby Area Types Page Page Configuring Neighbors for Nonbroadcast Networks Page Page Page Page Configuring Authentication at Different Hierarchical Levels for OSPF Version 2 Page Page Controlling the Frequency that the Same LSA Is Originated or Accepted for OSPF Page Creating a Virtual Link with MD5 Authentication to Area 0 for OSPF Page Page Page Summarizing Subnetwork LSAs on an OSPF ABR Page Redistributing Routes from One IGP into OSPF Page Page Page Configuring OSPF Shortest Path First Throttling Page Page Configuring Nonstop Forwarding for OSPF Version 2 Page Configuring OSPF Version 2 for MPLS Traffic Engineering Page Page Page RC-179 Sample Output for the show ospf mpls traffic-eng Command Verifying OSPF Configuration and Operation Configuring OSPFv3 Graceful Restart Enabling Graceful Restart Configuring the Maximum Lifetime of a Graceful Restart Configuring the Minimum Time Required Between Restarts Configuring the Helper Level of the Router Displaying Information About Graceful Restart Enabling Multicast-Intact for OSPFv2 Configuration Examples for Implementing OSPF on Cisco IOS XR Cisco IOS XR for OSPF Version 2 Configuration: Example CLI Inheritance and Precedence for OSPF Version 2: Example RC-190 MPLS TE for OSPF Version 2: Example ABR with Summarization for OSPFv3: Example The following example shows the prefix range 2300::/16 summarized fr om area 1 into the backbone: ABR Stub Area for OSPFv3: Example The following example shows that area 1 is configured as a stub area: ABR Totally Stub Area for OSPFv3: Example The following example shows that area 1 is configured as a totally stub area: Route Redistribution for OSPFv3: Example Virtual Link Configured Through Area 1 for OSPFv3: Example ABR 1 Configuration Virtual Link Configured with MD5 Authentication for OSPF Version 2: Example Page Page Implementing and Monitoring RIB on Cisco IOS XR Software Prerequisites for Implementing RIB on Cisco IOS XR Software Information About RIB Configuration Overview of RIB RIB Data Structures in BGP and Other Protocols RIB Administrative Distance RIB Support for IPv4 and IPv6 How to Deploy and Monitor RIB Verifying RIB Configuration Using the Routing Table Verifying Networking and Routing Problems RC-199 Displays local routes for receive entries in the routing table. interface instance protocol Configuration Examples for RIB Monitoring Output of show route Command: Example RC-201 Output of show route backup Command: Example The following is sample output from the show route backup command: Output of show route best-local Command: Example The following is sample output from the show route best-local command: Output of show route longer-prefixes Command: Example Output of show route next-hop Command: Example Page Page Implementing Routing Policy on Cisco IOS XR Software Prerequisites for Implementing Routing Policy Information About Implementing Routing Policy Routing Policy Language Routing Policy Language Overview Routing Policy Language Structure Names Sets as-path-set community-set extcommunity-set prefix-set Routing Policy Language Components Routing Policy Language Usage Page Routing Policy Configuration Basics Policy Definitions Parameterization Semantics of Policy Application Boolean Operator Precedence Multiple Modifications of the Same Attribute When Attributes Are Modified Default Drop Disposition Control Flow Policy Verification Range Checking Incomplete Policy and Set References Attached Policy Modification Verification of Attribute Comparisons and Actions Policy Statements Remark Disposition Action If Boolean Conditions apply Attach Points BGP Policy Attach Points Aggregation Dampening Neighbor Export Neighbor Import Network Show bgp Table Policy BGP Attributes and Operators Page OSPF Policy Attach Points OSPF Attributes and Operators OSPFv3 Policy Attach Points OSPFv3 Attributes and Operators IS-IS Policy Attach Points IS-IS Attributes and Operators Attached Policy Modification Nonattached Policy Modification Editing Routing Policy Configuration Elements Editing Routing Policy Configuration Elements Using the EMACS Editor RC-236 Editing Routing Policy Configuration Elements Using the CLI How to Implement Routing Policy Defining a Route Policy Attaching a Routing Policy to a BGP Neighbor Page Modifying a Routing Policy Using the Microemacs Editor Configuration Examples for Implementing Routing Policy Routing Policy Definition: Example Simple Inbound Policy: Example Modular Inbound Policy: Example Translating Cisco IOS Route Maps to Cisco IOS XR Routing Policy Language: Example Page Page Implementing Static Routes on Cisco IOS XR Software Prerequisites for Implementing Static Routes on Cisco IOS XR Information About Implementing Static Routes on Cisco IOS XR Static Route Functional Overview Default Administrative Distance Directly Connected Routes Recursive Static Routes Fully Specified Static Routes Floating Static Routes How to Implement Static Routes on Cisco IOS XR Software Configuring a Static Route Configuring a Floating Static Route Page Changing the Maximum Number of Allowable Static Routes Page Configuration Examples Configuring Traffic Discard: Example Configuring a Fixed Default Route: Example Configuring a Floating Static Route: Example Page INDEX A B C D E G H I L M N O Page P R Page S T U V W