Cisco Systems N3KC3048TP1GE Synchronization of Port Roles, Disabled State, Summary of Port States

Configuring Rapid PVST+

Understanding Rapid PVST+

•Forwards frames received from the attached segment.

•Forwards frames switched from another port for forwarding.

•Incorporates the end station location information into its address database.

•Receives BPDUs and directs them to the system module.

•Processes BPDUs received from the system module.

•Receives and responds to network management messages.

Disabled State

A LAN port in the disabled state does not participate in frame forwarding or STP. A LAN port in the disabled state is virtually nonoperational.

A disabled LAN port performs as follows:

•Discards frames received from the attached segment.

•Discards frames switched from another port for forwarding.

•Does not incorporate the end station location into its address database. (There is no learning, so there is no address database update.)

•Does not receive BPDUs from neighbors.

•Does not receive BPDUs for transmission from the system module.

Summary of Port States

The following table lists the possible operational and Rapid PVST+ states for ports and the corresponding inclusion in the active topology.

Table 8: Port State Active Topology
Operational Status	Port State	Is Port Included in the Active
		Topology?
Enabled	Blocking	No
Enabled	Learning	Yes
Enabled	Forwarding	Yes
Disabled	Disabled	No

Synchronization of Port Roles

When the switch receives a proposal message on one of its ports and that port is selected as the new root port, Rapid PVST+ forces all other ports to synchronize with the new root information.

	Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
74	OL-26590-01