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Cisco − Troubleshooting BGP

Table of Contents
Troubleshooting BGP.........................................................................................................................................1
Document ID: 22166................................................................................................................................1
Interactive: This document offers customized analysis of your Cisco device........................................1
Introduction..........................................................................................................................................................1
Before You Begin................................................................................................................................................1
Conventions............................................................................................................................................1
Prerequisites............................................................................................................................................1
Components Used...................................................................................................................................1
Main Troubleshooting Flowchart........................................................................................................................2
Troubleshooting BGP Neighbor Establishment...................................................................................................2
Troubleshooting Routes Missing from the Routing Table..................................................................................3
Troubleshooting Multihoming Inbound...............................................................................................................4
Troubleshooting BGP Route Advertisement.......................................................................................................5
Troubleshooting Multihoming Outbound............................................................................................................6
Related Information.............................................................................................................................................7

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To see more information. Prerequisites There are no specific prerequisites for this document. You can use Output Interpreter to display potential issues and fixes. The information presented in this document was created from devices in a specific lab environment. Components Used This document is not restricted to specific software and hardware versions. see the Cisco Technical Tips Conventions. To use Output Interpreter. Introduction Before You Begin Conventions Prerequisites Components Used Main Troubleshooting Flowchart Troubleshooting BGP Neighbor Establishment Troubleshooting Routes Missing from the Routing Table Troubleshooting Multihoming Inbound Troubleshooting BGP Route Advertisement Troubleshooting Multihoming Outbound Related Information Introduction This document provides troubleshooting information for common problems with Border Gateway Protocol (BGP). All of the devices used in this document started with a cleared (default) configuration. be logged in. or show tech−support command from your Cisco device. you must be a registered customer. To use. you must be a registered customer. or to go to the next flowchart. click the command boxes in red. you can use to display potential issues and fixes. Before You Begin Conventions For more information on document conventions. show ip bgp summary. be logged in. and have JavaScript enabled.Troubleshooting BGP Document ID: 22166 Interactive: This document offers customized analysis of your Cisco device. If you have the output of a show ip bgp. show ip bgp neighbor. If you are working in a live Cisco − Troubleshooting BGP . and have JavaScript enabled.

ensure that you understand the potential impact of any command before using it.network. Main Troubleshooting Flowchart Troubleshooting BGP Neighbor Establishment Cisco − Troubleshooting BGP .

Troubleshooting Routes Missing from the Routing Table Cisco − Troubleshooting BGP .

Troubleshooting Multihoming Inbound Cisco − Troubleshooting BGP .

Troubleshooting BGP Route Advertisement Cisco − Troubleshooting BGP .

Troubleshooting Multihoming Outbound Cisco − Troubleshooting BGP .

Related Information • BGP Support Page • Technical Support − Cisco Systems All contents are Copyright © 1992−2005 Cisco Systems. 2006 Document ID: 22166 Cisco − Troubleshooting BGP . All rights reserved. Updated: Jan 10. Inc. Important Notices and Privacy Statement.