Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 414)

Changing the maximum number of shared BGP4 paths
To change the maximum number of BGP4 shared paths, enter commands such as the following.
device(config)# router bgp
device(config-bgp-router)# maximum-paths 4
device(config-bgp-router)# write memory
Syntax: [no] maximum-paths num | use-load-sharing
The number parameter specifies the maximum number of paths across which the device can balance
traffic to a given BGP4 destination. The number value range is 2 through 8 and the default is 1.
When the use-load-sharing option is used in place of the number variable, the maximum IP ECMP
path value is determined solely by the value configured using theip load-sharing command.
Customizing BGP4 Multipath load sharing
By default, when BGP4 Multipath load sharing is enabled, both IBGP and EBGP paths are eligible for
load sharing, while paths from different neighboring autonomous systems are not eligible. You can
change load sharing to apply only to IBGP or EBGP paths, or to support load sharing among paths
from different neighboring autonomous systems.
To enable load sharing of IBGP paths only, enter the following command at the BGP4 configuration
level of the CLI.
device(config-bgp-router)# multipath ibgp
To enable load sharing of EBGP paths only, enter the following command at the BGP4 configuration
level of the CLI.
device(config-bgp-router)# multipath ebgp
To enable load sharing of paths from different neighboring autonomous systems, enter the following
command at the BGP4 configuration level of the CLI.
device(config-bgp)# multipath multi-as
Syntax: [no] multipath ebgp | ibgp | multi-as
The ebgp, bgp, and multi-as parameters specify the change you are making to load sharing:
• ebgp - Multipath load sharing applies only to EBGP paths. Multipath load sharing is disabled for
IBGP paths.
• ibgp - Multipath load sharing applies only to IBGP paths. Multipath load sharing is disabled for
EBGP paths.
• multi-as - Multipath load sharing is enabled for paths from different autonomous systems.
By default, load sharing applies to EBGP and IBGP paths, and does not apply to paths from different
neighboring autonomous systems.
Enhancements to BGP4 Multipath load sharing
Enhancements to BGP4 Multipath load sharing allows support for load sharing of BGP4 routes in IP
ECMP even if the BGP4 Multipath load sharing feature is not enabled through the use-load-sharing
option to the maximum-paths command. Using the following commands, you can also set separate
values for IGMP and EGMP multipath load sharing.
Changing the maximum number of shared BGP4 paths
414 FastIron Ethernet Switch Layer 3 Routing Configuration Guide
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