In the network shown in the figure below, the host logs in to router A through Telnet, and then obtains the configuration file of router B through FTP on the remote interface. How many TCP connections exist on router A at this time?

By default, in the SNMP protocol, which port number does the agent process use to send alarm messages to the NMS?

As shown in the figure below, which port of the following switches will be blocked?

Which of the following authentication methods do not need to enter a user name and password.

Only one SSID can be bound to an AP radio.