The interval between the generation of configuration messages by the root bridge for all instances on the device is the hello time. The maximum-aging timer is the number of seconds that a device waits without receiving spanning tree configuration messages before attempting a reconfiguration. You can configure the maximum hops inside the region and apply it to all MST instances in that region. The hop count achieves the same result as the message-age information (triggers a reconfiguration).
You use the Spanning Tree pane to configure the hello time, forwarding delay time, maximum aging time, and maximum hop count for MST (see Figure 1).
When you configure virtual port channels (vPCs) on the switch, we recommend that you set the STP hello time to 4 seconds on both the primary and secondary vPC peer devices.
See the Cisco DCNM Interfaces Configuration Guide, Release 4.2, for more information on vPCs.