peer load-balancing (BGP-IPv4 multicast address family view)

Function

The peer load-balancing command enables MBGP peer based load balancing.

The undo peer load-balancing command restores the default configuration.

By default, MBGP load balancing is not enabled.

Format

peer peerIpv4Addr load-balancing [ as-path-ignore | as-path-relax ]

undo peer peerIpv4Addr load-balancing [ as-path-ignore | as-path-relax ]

Parameters

Parameter	Description	Value
peerIpv4Addr	Specifies the IP address of an MBGP peer.	The value is in dotted decimal notation.
as-path-ignore	Prevents the router from comparing AS_Path attributes when selecting routes for load balancing.	-
as-path-relax	Configures the device to ignore comparing the AS_Path attributes of the same length when selecting routes for load balancing.	-

Parameter

Description

Value

peerIpv4Addr

Specifies the IP address of an MBGP peer.

The value is in dotted decimal notation.

as-path-ignore

Prevents the router from comparing AS_Path attributes when selecting routes for load balancing.

as-path-relax

Configures the device to ignore comparing the AS_Path attributes of the same length when selecting routes for load balancing.

Views

BGP-IPv4 multicast address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

On large networks, there may be multiple valid routes to the same destination. BGP, however, advertises only the optimal route to its peers. This may result in unbalanced traffic on different routes. To prevent this problem, configure load balancing.

After the peer load-balancing command is run, BGP peer-based load balancing is implemented only when the following conditions are met:

The routes are received from the specified peer.
The optimal route and optimal equal-cost routes exist.
The AS_Path attribute is the same as that of the optimal route, or as-path-ignore or as-path-relax is specified in the peer load-balancing command.
a.If as-path-ignore is specified, the device ignores comparing AS_Path attributes when selecting routes for load balancing. In this case, routes can participate in load balancing even if their AS_Path attributes are different.
b.If as-path-relax is specified, the device ignores comparing the AS_Path attributes of the same length when selecting routes for load balancing. In this case, routes cannot participate in load balancing if their AS_Path attributes are of different lengths. For example, the AS_Path attribute of route A is 10, and the AS_Path attribute of route B is 10, 20. Because the two AS_Path attributes are of different lengths, the two routes cannot participate in load balancing.

Precautions

The maximum load-balancing and the peer load-balancing commands are mutually exclusive.

Example

# Enable load balancing among routes learned from peer 1.1.1.1 and among routes learned from peer 2.2.2.2.

<HUAWEI> system-view
[~HUAWEI] bgp 100
[*HUAWEI-bgp] peer 1.1.1.1 as-number 100
[*HUAWEI-bgp] peer 2.2.2.2 as-number 100
[*HUAWEI-bgp] ipv4-family multicast
[*HUAWEI-bgp-af-multicast] peer 1.1.1.1 enable
[*HUAWEI-bgp-af-multicast] peer 2.2.2.2 enable
[*HUAWEI-bgp-af-multicast] peer 1.1.1.1 load-balancing
[*HUAWEI-bgp-af-multicast] peer 2.2.2.2 load-balancing