Brocade FastIron Ethernet Switch Administration Guide - Manual (Page 135)

If the path selected by the device becomes unavailable, the IPv6 neighbor should change state and
trigger the update of the destination in the hardware.
Brocade FastIron devices support network-based ECMP load-sharing methods for IPv6 traffic. The
Brocade device distributes traffic across equal-cost paths based on a XOR of some bits from the MAC
source address, MAC destination address, IPv6 source address, IPv6 destination address, IPv6 flow
label, IPv6 next header. The software selects a path based on a calculation involving the maximum
number of load-sharing paths allowed and the actual number of paths to the destination network. This is
the default ECMP load-sharing method for IPv6.
You can manually disable or enable ECMP load sharing for IPv6 and specify the number of equal-cost
paths the device can distribute traffic across. In addition, you can display information about the status of
ECMP load-sharing on the device.
Disabling or re-enabling ECMP load sharing for IPv6
ECMP load sharing for IPv6 is enabled by default. To disable the feature, enter the following command.
device(config)#no ipv6 load-sharing
If you want to re-enable the feature after disabling it, you must specify the number of load-sharing
paths. The maximum number of paths the device supports is a value from 2-8. By entering a command
such as the following, iPv6 load-sharing will be re-enabled.
device(config)#ipv6 load-sharing 4
Syntax: [no] ipv6 load-sharing num
The num parameter specifies the number of paths and can be from 2-8. The default is 4.
Changing the maximum load sharing paths for IPv6
By default, IPv6 ECMP load sharing allows traffic to be balanced across up to four equal paths. You can
change the maximum number of paths the device supports to a value from 2-8.
To change the number of ECMP load sharing paths for IPv6, enter a command such as the following.
device(config)#ipv6 load-sharing 6
Syntax: [no] ipv6 load-sharing [ num ]
The num parameter specifies the number of paths and can be from 2-8. The default is 4.
Enabling support for network-based ECMPload sharing for IPv6
Network-based ECMP load sharing is supported. In this configuration, traffic is distributed across equal-
cost paths based on the destination network address. Routes to each network are stored in CAM and
accessed when a path to a network is required. Because multiple hosts are likely to reside on a
network, this method uses fewer CAM entries.
Displaying ECMP load-sharing information for IPv6
To display the status of ECMP load sharing for IPv6, enter the following command.
device#show ipv6
Global Settings
Disabling or re-enabling ECMP load sharing for IPv6
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