The router starts to generate a warning message. Threshold-An optional integer value that specifies at what percentage maximum-value is configured.
Maximum-Represents the maximum number of prefixes allowed from the neighbor. The command syntax used in order to configure the BGP Maximum-Prefix feature is: neighbor maximum-prefix In this section, you are presented with the information to configure the features described in this document. Refer to Cisco Technical Tips Conventions for more information on document conventions.
#Maximum action update software
If your network is live, make sure that you understand the potential impact of any command.Īccess Cisco Feature Navigator ( registered customers only) in order to determine which Cisco IOS Software versions you can use with this feature. All of the devices used in this document started with a cleared (default) configuration. The information in this document was created from the devices in a specific lab environment.
#Maximum action update series
The information in this document is based on these software and hardware versions:Ĭisco 2500 Series Routers on Cisco IOS® Software Releases 12.2(27) Prerequisites RequirementsĬisco recommends readers of this document have basic understanding of Configuring a BGP Network. For further information, refer to BGP Restart Session After Maximum-Prefix Limit. No intervention from the network operator is required when this feature is enabled. The enhancement allows the user to automatically reestablish a peering session that has been brought down because the configured Maximum-Prefix limit is exceeded. Note: An enhancement to this feature is introduced in Cisco IOS ® Software Release 12.0(22)S and 12.2(15)T. Available actions could either be to bring down the session and to keep the BGP neighbor relationship down until you use the clear ip bgp x.x.x.x command or, alternatively, to only log a warning message. Know the action to take in case the remote BGP peer sends more prefixes than those expected. Set a threshold a little higher than the number of BGP prefixes expected to be received during normal operations. Know how many routes the remote BGP peering router normally sends. When you plan to use this feature, consider these key points: With the neighbor maximum-prefix command, it is possible to protect a router against this situation. A BGP problem could disrupt internal network connectivity. If this same router is peering with BGP and also performs critical routing functions within a network, this overhead could turn out bad. The Maximum-Prefix feature is useful when, at a change of outbound policy at the remote peering site, a router starts to receive more routes than the router memory can take. This feature is commonly used for external BGP peers, but can be applied to internal BGP peers also. By default, this feature allows a router to bring down a peer when the number of received prefixes from that peer exceeds the configured Maximum-Prefix limit. The BGP Maximum-Prefix feature allows you to control how many prefixes can be received from a neighbor. This document provides configuration and troubleshooting information on the Border Gateway Protocol (BGP) Maximum-Prefix feature.