STP的五种状态

1. Blocking State

·         Discards frames received on the port（不收数据帧）

·         Discards frames switched from another interface for forwarding（不转发从其它端口接收的数据帧）

·         Does not learn addresses（不学习MAC地址）

·         Receives BPDUs（接收BPDU）

2. Listening State

·         Discards frames received on the port（不收数据帧）

·         Discards frames switched from another interface for forwarding（不转发从其它端口接收的数据帧）

·         Does not learn addresses（不学习MAC地址）

·         Receives BPDUs（接收BPDU）

3. Learning State

·         Discards frames received on the port（不收数据帧）

·         Discards frames switched from another interface for forwarding（不转发从其它端口接收的数据帧）

·         Learns addresses（学习MAC地址）

·         Receives BPDUs （接收BPDU）

4. Forwarding State

·         Receives and forwards frames received on the port（接收并且转发数据帧）

·         Forwards frames switched from another port（转发从其它端口接收的数据帧）

·         Learns addresses（学习MAC地址）

·         Receives BPDUs（接收BPDU）

5. Disabled State

·         Discards frames received on the port（不收数据帧）

·         Discards frames switched from another interface for forwarding（不转发从其它端口接收的数据帧）

·         Does not learn addresses（不学习MAC地址）

·         Does not receive BPDUs（不接收BPDU）

这个列表很清晰地列出各种状态下端口对BPDU和数据帧和MAC地址的处理情况。