下面是从Cisco的Document中摘抄的五种状态的行为，我稍微增加了点英文的翻译：
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。