Cisco Systems OL-14361-01 manual Routing Policy Language Line and Policy Limits, 127

Chapter 5 Configuring Additional Router Features

Configuration Limiting

A cease-notification message is sent to the neighbor and the peering with the neighbor is terminated when the number of prefixes received from the peer for a given address family exceeds the maximum limit (either set by default or configured by the user) for that address family.

However, if the warning-onlykeyword (for the maximum-prefixcommand) is configured, the Cisco IOS XR software sends only a log message, but continues peering with the sender. If the peer is terminated, the peer stays down until the clear bgp command is issued.

The same set of actions (sending cease notification followed by the termination of the peering) is taken for a neighbor with which peering has already been established if you decide to configure a maximum that is less than the number of prefixes that have already been received from the neighbor.

Examples

The following example shows how to set the BGP configuration limits:

RP/0/RP1/CPU0:router# configure

RP/0/RP1/CPU0:router(config)# router bgp 100

RP/0/RP1/CPU0:router(config-bgp)# neighbor 10.1.1.1

RP/0/RP1/CPU0:router(config-bgp-nbr)# remote-as 1

RP/0/RP1/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast

RP/0/RP1/CPU0:router(config-bgp-nbr-af)# maximum-paths 4

RP/0/RP1/CPU0:router(config-bgp-nbr-af)# maximum-prefix 100000

RP/0/RP1/CPU0:router(config-bgp-nbr-af)# commit

RP/0/RP1/CPU0:Mar 30 19:13:16 : config[65740]: %LIBTARCFG-6-COMMIT : Configuration committed by user 'cisco'. Use 'show configuration commit changes 1000000544' to view the changes.

RP/0/RP1/CPU0:Mar 30 19:13:17 : config[65740]: %SYS-5-CONFIG_I : Configured from console by cisco

RP/0/RP1/CPU0:router(config-bgp-nbr-af)#

Routing Policy Language Line and Policy Limits

Two limits for Routing Policy Language (RPL) configurations exist:

1.Number of RPL lines: The number of configuration lines entered by the user, including the beginning and ending statements (that is “route-policy”). The number of configuration lines for sets is also included.

2.Number of RPL policies: The number of policies that can be configured on the router. Policies are

counted only once: Multiple use of the same policy counts as a single policy toward the limit 1.

The limits for RPL lines and policies are summarized in Table 5-8. You can change the default values up to the absolute maximum, but you cannot change the value to a number less than the number of items that are currently configured.

Table 5-8		Maximum Lines of RPL: Configuration Limits and Commands
			Default	Absolute		Show Current Settings
			Maximum	Maximum	Configuration Command	Command
	Limit Description		Limit	Limit	(Global Configuration Mode)	(EXEC Mode)
	Maximum number of RPL lines		65,536	131,072	rpl maximum lines n	show rpl maximum lines
	Maximum number of RPL policies		3500	5000	rpl maximum policies n	show rpl maximum
						policies
					Cisco IOS XR Getting Started Guide
	OL-14361-01						5-127