D-Link DES-3326 User Manual - Troubleshooting Stp
Manual is about: 24-Port Fast Ethernet Plus 2-Port Gigabit Module Layer 3 Switch
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DES-3326 Layer 3 Fast Ethernet Switch User’s Guide
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Understanding and Troubleshooting the Spanning Tree Protocol
Troubleshooting STP
Spanning Tree Protocol Failure
A failure in the STA generally leads to a bridging loop. A bridging
loop in an STP environment comes from a port that should be in
the blocking state, but is forwarding packets.
In this example, B has been elected as the designated bridge and
port 2 on C is in the blocking state. The election of B as the
designated bridge is determined by the exchange of BPDUs
between B and C. B had a better BPDU than C. B continues
sending BPDUs advertising its superiority over the other bridges
on this LAN. Should C fail to receive these BPDUs for longer than