configure isis area add summary-address

configure isis area area_name add summary-address [ipv4_address_mask | ipv6_address_mask] {level [1 | 2]}


This command adds an IPv4 or IPv6 summary address for the specified level on the specified router process.

Syntax Description

area_name Specifies the router process to which the summary address is to be added.
ipv4_address_mask Specifies an IPv4 summary address.
ipv6_address_mask Specifies an IPv6 summary address.
level Specifies the IS-IS level for the summary address. The level 1 option summarizes level 2 routes leaked to level 1. The level 2 option summarizes level 1 routes that are advertised into level 2.


No summarization.

Usage Guidelines

Route summaries are useful for minimizing the number of LSPs required to describe reachability for an area. The summary address is advertised instead of the actual reachable addresses. This is particularly useful for L1/L2 routers in which the summary address is used in a single LSP instead of including a part or all of the addresses reachable in its level 1 area.

Note that a summary address is only advertised if at least one route matches the summary address. If there is no route present that matches the summary address exactly, a blackhole route is installed for the summary address. If an interlevel filter permits any route matched by the summary address, and that route is present, the summary address is advertised.

If multiple summary addresses are installed in which one or more supersede each other ( and, for example), only the more specific summary addresses are advertised.


The following command adds an IPv4 summary address to areax:

configure isis area areax add summary-address


This command was first available in ExtremeXOS 12.1.

Platform Availability

This command is available on platforms with a Core or Premier license as described in the ExtremeXOS and Switch Engine 31.7 Feature License Requirements document.