Which of the following IEEE 802.11 standards support operation in the 5GHz frequency band? (Multiple choice)

On which layer of the OSI reference model does the Ethernet switch work?

The information shown in the figure is the port status information displayed on a switch running STP. According to this information, which of the following description is wrong?

Which state does the OSPF protocol use to indicate that the adjacency relationship has been established?

If the network address of a network is 192.168.1.0, then its broadcast address must be 192.168.1.255.