Huawei S6700 Series Configuration Manual page 451

S6700 Series Ethernet Switches
Configuration Guide - IP Routing
l
Issue 01 (2012-03-15)
1. Run:
system-view
The system view is displayed.
2. Run:
bgp as-number
The BGP view is displayed.
3. Run:
ipv4-family unicast
The IPv4 unicast address family view is displayed.
4. Run:
maximum load-balancing [ ebgp | ibgp ] number
The number of BGP routes to be used for load balancing is set.
By default, the number of BGP routes to be used for load balancing is 1, meaning that
load balancing is not implemented.
– ebgp indicates that load balancing is implemented only among EBGP routes.
– ibgp indicates that load balancing is implemented only among IBGP routes.
– If neither ebgp nor ibgp is specified, both EBGP and IBGP routes participate in
load balancing, and the number of EBGP routes to be used for load balancing is
the same as the number of IBGP routes to be used for load balancing.
NOTE
The maximum load-balancing number command cannot be configured together with the
maximum load-balancing ebgp number or maximum load-balancing ibgp number
command.
When routes with the same destination addresses carry out load balancing on the public
network, the system determines the type of optimal routes first. If the optimal routes are IBGP
routes, only IBGP routes carry out load balancing. If the optimal routes are EBGP routes, only
EBGP routes carry out load balancing. This means that load balancing cannot be implemented
among IBGP and EBGP routes with the same destination address.
5. (Optional) Run:
load-balancing as-path-ignore
The switch is configured not to compare the AS-Path attributes of the routes to be
used for load balancing.
By default, the switch compares the AS-Path attributes of the routes to be used for
load balancing.
NOTE
l If there are multiple routes to the same destination but these routes pass through different
ASs, load balancing cannot be implemented among these routes by default. To implement
load balancing among these routes, run the load-balancing as-path-ignore command.
After the load-balancing as-path-ignore command is run, the device no longer compares
the AS-Path attributes of the routes to be used for load balancing. Therefore, exercise
caution when using this command.
l The load-balancing as-path-ignore and bestroute as-path-ignore commands are
mutually exclusive.
Set the maximum number of EBGP and IBGP routes to be used for load balancing.
This configuration is used in a VPN where a CE is dual-homed to two PEs. When the CE
and one PE belong to an AS and the CE and the other PE belong to a different AS, you can
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
7 BGP Configuration
432