balance

Use balance to enable load balancing and specify the maximum number of BGP ECMP routes for load balancing.

Use undo balance to disable load balancing.

Syntax

balance number

undo balance

Default

Load balancing is not enabled.

Views

BGP IPv4 unicast address family view, BGP-VPN IPv4 unicast address family view, BGP IPv6 unicast address family view, BGP-VPN IPv6 unicast address family view

Predefined user roles

network-admin

mdc-admin

Parameters

number: Specifies the maximum number of BGP ECMP routes for load balancing. When it is set to 1, load balancing is disabled.

Usage guidelines

Unlike IGP, BGP has no explicit metric for making load balancing decision. Instead, it implements load balancing by modifying route selection rules. If multiple BGP routes destined for a network meet the following conditions, the device selects the specified number of routes from these routes for load balancing:

• The routes have the same AS_PATH, ORIGIN, LOCAL_PREF, and MED attributes.

• All the routes are reflected by a route reflector, or none of the routes is reflected by a route reflector.

The value range for the number argument depends on the max-ecmp-num command. If you set the maximum number of ECMP routes to m by using the max-ecmp-num command and reboot the device, the number argument in the balance command is in the range of 1 to m.

Examples

# In BGP IPv4 unicast address family view, enable load balancing and specify the maximum number of BGP ECMP routes used for load balancing as 2.

<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family ipv4 unicast
[Sysname-bgp-ipv4] balance 2

# In BGP-VPN IPv6 unicast address family view, enable load balancing and specify the maximum number of BGP ECMP routes for load balancing as 2.

<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ip vpn-instance vpn1
[Sysname-bgp-vpn1] address-family ipv6 unicast
[Sysname-bgp-ipv6-vpn1] balance 2

Related commands

max-ecmp-num