Port States - Cisco N5010P-N2K-BE Software Configuration Manual

Chapter 8 Configuring Rapid PVST+
S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
Figure 8-5
Bridge_ID=4
Root_ID =1
Alternate port
Backup port
Designated port
Root port

Port States

This section describes the Rapid PVST+ and MST port states:
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Rapid PVST+ Port State Overview
Propagation delays can occur when protocol information passes through a switched LAN. As a result,
topology changes can take place at different times and at different places in a switched network. When
a LAN port transitions directly from nonparticipation in the spanning tree topology to the forwarding
state, it can create temporary data loops. Ports must wait for new topology information to propagate
through the switched LAN before starting to forward frames.
Each LAN port on a software using Rapid PVST+ or MST exists in one of the following four states:
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OL-16597-01
Sample Topology Demonstrating Port Roles
Bridge_ID=2
Root_ID =1
Bridge_ID=5
Root_ID =1
Rapid PVST+ Port State Overview, page 8-11
Blocking State, page 8-12
Learning State, page 8-12
Forwarding State, page 8-12
Disabled State, page 8-13
Summary of Port States, page 8-13
Blocking—The LAN port does not participate in frame forwarding.
Learning—The LAN port prepares to participate in frame forwarding.
Forwarding—The LAN port forwards frames.
Disabled—The LAN port does not participate in STP and is not forwarding frames.
Bridge_ID=1
Root_ID =1
Bridge_ID=3
Root_ID =1
Bridge_ID=6
Root_ID =1
Active link
Blocked link
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
Information About Rapid PVST+
Bridge_ID=7
Root_ID =1
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