将交换机的端口设置为边缘端口后，为避免误将此端口与交换机互联，可以采用的技术是（） A:  root protection B:  BPDU protection C:  Loop protection D:  该端口STP disable

在同一端口上启用了BPDU防护和BPDU过滤，以下描述正确的是（） A: BPDU防护生效，BPDU过滤失效 B: BPDU防护失效，BPDU过滤生效 C: BPDU防护和BPDU过滤同时生效 D: BPDU防护和BPDU过滤冲突，都失效

运行STP协议的交换机采用二种BPDU,一种是配置BPDU,另一种指示拓扑变化的BPDU,后者的BPDU类型字段是

STP交换机会发送BPDU。关于BPDU的说法正确的是()。(多选)

Biodiversity protection measurements include legal protection and sustainable management of wild animals. （ ）

BPDU防护依赖下列哪种特性（）. A: portfast B: BPDU过滤 C: UPlinkfast D: 根防护

Which of the following statements about relationship between environmental protection and economic development is wrong ( )? A: Environmental protection is not an industry. B: Environmental protection is an industry. C: Both environmental protection and economic development can be realized at the same time. D: Both environmental protection and economic development cannot be realized at the same time.

STP中有两种BPDU，一种是配置BPDU，另外一种是拓扑改变通知BPDU，关于这两种BPDU的说法正确的是（）。 A: 在网络拓扑发生变化后，下游设备会向上游设备发送三次TCNBPDU报文 B: 在初始化过程中，每个桥都主动发送配置BPDU C: 配置BPDU的长度至少要16个字节，包含了桥I D: 路径开销和端口ID等参数 E: 当根端口收到配置BPDU时，根端口所在的设备会向自己的每一个指定端口复制一份配置BPDU

8 A) An environmental protection law has been passed. B) An environmental protection law needs to be passed. C) This passage is about environmental protection. D) The environmental protection law will take effect soon. A: A) An environmental protection law has been passed. B: B) An environmental protection law needs to be passed. C: C) This passage is about environmental protection. D: D) The environmental protection law will take effect soon.

在STP协议中，配置信息是通过BPDU协议数据包来进行转发的，那么对于配置BPDU报文，以下说法正确的是（） A: 配置BPDU不能在指定端口上发送 B: 配置BPDU只能在指定端口上发送 C: 配置BPDU能够在任意角色的端口上发送 D: 以上说法都不正确