Brocade Communications Systems FastIron X Series User Manual

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
dierent 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 dierent neighboring autonomous systems.
To enable load sharing of IBGP paths only, enter the following command at the BGP4 conguration 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
conguration level of the CLI.
device(config-bgp-router)# multipath ebgp
To enable load sharing of paths from dierent neighboring autonomous systems, enter the following command at the BGP4
conguration 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
dierent autonomous systems.
By default, load sharing applies to EBGP and IBGP paths, and does not apply to paths from dierent 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 IBGP and EBGP multipath load sharing.
To set the number of equal-cost multipath IBGP routes or paths that will be selected, enter commands such as the following.
device(config)# router bgp
device(config-bgp)# maximum-paths ibgp
Syntax: [no] maximum-paths ibgp number
The number variable
species the number of equal-cost multipath IBGP routes that will be selected. The range is 2 to 8. If the value is
set to 1, BGP4 level equal-cost multipath is disabled for IBGP routes.
To set the number of equal-cost multipath EBGP routes or paths that will be selected, enter commands such as the following.
device(config)# router bgp
device(config-bgp)# maximum-paths ebgp
Syntax: [no] maximum-paths ebgp num
The number variable
species the number of equal-cost multipath EBGP routes that will be selected. The range is 2 to 8. If the value is
set to 1, BGP4 level equal-cost multipath is disabled for EBGP routes.
Specifying a list of networks to advertise
By default, the device sends BGP4 routes only for the networks you either identify with the network command or are redistributed into
BGP4 from OSPF, RIP, or connected routes.
Optional BGP4 conguration tasks
FastIron Ethernet Switch Layer 3 Routing
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Brocade Communications Systems FastIron X Series Specifications

General

Brand	Brocade Communications Systems
Model	FastIron X Series
Category	Switch
Language	English