Brocade Multi-Service IronWare Multicast Configuration Guide (Supporting R05.6.00) - Manual (Page 25)

Multi-Service IronWare Multicast Configuration Guide 13
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Multicast non-stop routing
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Multicast non-stop routing
Multicast non-stop routing (NSR) provides hitless upgrade and switchover support for all IPv4
multicast, including default and non-default VRFs for IPv4 PIM-DM, PIM-SM, and PIM-SSM.
Multicast NSR is not supported for IPv6 multicast and DVMRP. The software multicast state is kept
in sync between the active and standby MPs. As the Brocade system enters a hitless upgrade or
switchover state, the standby MP will take over as the new active MP. The new active MP will carry a
pre-installed multicast state that was originally supported by the previous MP. The new active MP
will revalidate the pre-installed multicast state, and pick up any new changes as needed before
marking the multicast state as operational. When the LP is ready to complete the hitless upgrade
or switchover process, the operational multicast state will be downloaded to the LP CPU. When the
LP resets, and the outage of the LP CPU occurs, pre-existing hardware forwarding multicast traffic
will continue to flow without disruption, and the hardware multicast forwarding state is retained in
the LP hardware.
Multicast NSR is globally enabled across all VRFs by configuring the ip multicast-nonstop-routing
command. For more information on configuring the ip multicast-nonstop-routing command, refer to
“Configuring multicast non-stop routing” .
NOTE
During hitless reload, if any changes occur to the existing multicast forwarding records, then
multicast receivers of the same forwarding records may see traffic loss.
NOTE
Hitless upgrade support for multicast NSR is supported only on Brocade NetIron XMR and Brocade
MLX series devices.
Configuration considerations
• Multicast NSR is not supported for IPv6 multicast, DVMRP, and layer 2 multicast.
• When multicast NSR is turned on, unicast routing must be protected by NSR or graceful restart
on all multicast VRFs.
• Any multicast flow that does not have a hardware CAM entry programmed prior to hitless
upgrade or switchover will not be protected under multicast NSR. The multicast entry for such
a flow shall be recreated upon the completion of the NSR process.
Configuring multicast non-stop routing
To globally enable multicast non-stop routing for all VRFs, enter the ip multicast-nonstop-routing
command on the CLI as shown in the example below.
Brocade(config)#ip multicast-nonstop-routing
Syntax: ip multicast-nonstop-routing
During a hitless upgrade and switchover on the MP, the following syslog message is generated on
the CLI.
Feb 3 14:09:58 Mcastv4 detected MP switchover, set switchover in progress to TRUE
Feb 3 14:10:07 Mcastv4 confirms unicast RTM is ready
Feb 3 14:10:07 Mcastv4 switchover done, set switchover in progress mode to FALSE