A wireless client cannot connect to an 802.11 network even though the network is visible. Which is a plausible reason?

A wireless client cannot connect to an 802.11 network even though the network is visible. Which is a plausible reason?

• A. The WAP does not recognize the client's MAC address.
• B. The SSID broadcast is disabled.
• C. The client password is incorrect.
• D. The network channel is congested.

Answer: (A)

When a wireless client can’t connect even though the network is visible, access control at the access point can be the blocking factor. Many APs use MAC address filtering to allow only devices with specific hardware addresses to associate. If the client’s MAC address isn’t in that allowed list, the AP won’t complete the connection, so the user can see the network (SSID is being broadcast) but can’t join it. This makes MAC filtering a plausible reason for a failed connection in a visible network. Why the other ideas fit less well: if the SSID were hidden, the network wouldn’t be visible at all, so visibility wouldn’t be the problem. If the password were incorrect, the client would eventually fail during authentication, but the scenario emphasizes the network is visible, and MAC filtering is a common, direct cause that blocks access before credentials are even checked. Channel congestion would degrade performance or reliability, not typically prevent a fresh connection outright.

When a wireless client can’t connect even though the network is visible, access control at the access point can be the blocking factor. Many APs use MAC address filtering to allow only devices with specific hardware addresses to associate. If the client’s MAC address isn’t in that allowed list, the AP won’t complete the connection, so the user can see the network (SSID is being broadcast) but can’t join it. This makes MAC filtering a plausible reason for a failed connection in a visible network.

Why the other ideas fit less well: if the SSID were hidden, the network wouldn’t be visible at all, so visibility wouldn’t be the problem. If the password were incorrect, the client would eventually fail during authentication, but the scenario emphasizes the network is visible, and MAC filtering is a common, direct cause that blocks access before credentials are even checked. Channel congestion would degrade performance or reliability, not typically prevent a fresh connection outright.