DES-3326S Layer 3 Fast Ethernet Switch User’s Guide
Understanding and Troubleshooting the Spanning Tree Protocol
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to transition its port 2 from the blocking state to the
forwarding state.
It should be noted: A port must continue to receive BPDUs
advertising superior paths to remain in the blocking state.
There are a number of circumstances in which the STA can
fail – mostly related to the loss of a large number of BPDUs.
These situations will cause a port in the blocking state to
transition to the forwarding state.
Full/Half Duplex Mismatch
A mismatch in the duplex state of two ports is a very common
configuration error for a point-to-point link. If one port is
configured as a full duplex, and the other port is left in auto-
negotiation mode, the second port will end up in half-duplex
because ports configured as half- or full-duplex do not
negotiate.
