summary-address

Use this command to create an aggregate IS-IS address for summarization of routes.

Syntax

summary-address ip-address/length
no summary-address ip-address/length

Parameters

ip-address/length Specifies an IP address in dotted notation followed by the length.

Defaults

None.

Mode

IS-IS router configuration for IPv4 addresses.

IPv6 unicast address family configuration for IPv6 addresses.

Usage

Summarizing addresses reduces the number of LSPs and the size of the link state database. Multiple addresses can be summarized for a given IS-IS instance.

To summarize a unicast IPv6 address, you must be in the IPv6 unicast family address configuration mode. Use address-family to enter IPv6 unicast family address configuration mode.

The “no” form of this command deletes the IS-IS aggregate address configuration.

Example

This example shows how to apply address summarization to prefix 20.10.1.0/24:

System(rw)->configure
System(rw-config)->router isis
System(rw-config-isis)->summary-address 20.10.1.0/24
System(rw-config-isis)->

This example shows how to apply address summarization to prefix 2003:2010::0/64:

System(rw)->configure
System(rw-config)->router isis
System(rw-config-isis)->address-family ipv6 unicast
System(rw-config-isis-af)->summary-address 2003:2010::0/64
System(rw-config-isis-af)->