Ecmp – Alcatel-Lucent 7750 SR OS User Manual

Page 88

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Configuration Commands

Page 88

7750 SR OS Router Configuration Guide

Syntax

confederation confed-as-num members as-number [as-number...up to 15 max]
no confederation [confed-as-num members as-number...up to 15 max]

Context

config>router

Description

This command creates confederation autonomous systems within an AS.

This technique is used to reduce the number of IBGP sessions required within an AS. Route
reflection is another technique that is commonly deployed to reduce the number of IBGP sessions.

The no form of the command deletes the specified member AS from the confederation.

When no members are specified in the no statement, the entire list is removed and confederation is
disabled.

When the last member of the list is removed, confederation is disabled.

Default

no confederation - no confederations are defined.

Parameters

confed-as-num — The confederation AS number expressed as a decimal integer.

Values

1 - 65535

members member-as-numThe AS number(s) of members that are part of the confederation,

expressed as a decimal integer. Up to 15 members per confed-as-num can be configured.

Values

1 - 65535

ecmp

Syntax

ecmp max-ecmp-routes
no ecmp

Context

config>router

Description

This command enables ECMP and configures the number of routes for path sharing; for example, the
value 2 means two equal cost routes will be used for cost sharing.

ECMP can only be used for routes learned with the same preference and same protocol. See the
discussion on preferences in the static-route command.

When more ECMP routes are available at the best preference than configured in max-ecmp-routes,
then the lowest next-hop IP address algorithm is used to select the number of routes configured in
max-ecmp-routes.

The no form of the command disables ECMP path sharing. If ECMP is disabled and multiple routes
are available at the best preference and equal cost, then the route with the lowest next-hop IP address
is used.

Default

no ecmp

Parameters

max-ecmp-routes — The maximum number of equal cost routes allowed on this routing table

instance, expressed as a decimal integer. Setting ECMP max-ecmp-routes to 1 yields the same
result as entering no ecmp.

Values

0 — 16

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