When you install two management modules (nodes) in a BlackDiamond chassis or when redundancy is available in a SummitStack, one node assumes the role of primary and the another node assumes the role of backup node.
Note
This section applies only to modular switches.
Note
Not all platforms support hitless failover in the same software release. To verify if the software version you are running supports hitless failover, see the following table in Managing the Switch. For more information about protocol, platform, and MSM support for hitless failover, see Understanding Hitless Failover Support.
Note
If you use 802.1X network login, authenticated clients remain authenticated during failover; however, shortly after failover, all authenticated clients automatically re-authenticate themselves. Re-authentication occurs without user intervention.
Note
Before initiating failover, review the section Synchronizing Nodes—Modular Switches and SummitStack Only to confirm that your switch (or SummitStack) and both (or all) nodes are running software that supports the synchronize command.