A wireless client with an 802.11b/g network card cannot connect to an 802.11b/g basic service set, and the access point client list shows no active wireless LAN clients. Which configuration problem on the client is the most likely cause of this failure to associate?

Introduction / Context:
In enterprise and small office wireless LANs, a very common support issue is a user reporting that a wireless client cannot connect to an access point or basic service set. Understanding which configuration parameters must match between the client and the access point is critical for quickly diagnosing why a client does not even appear in the access point association or client list.

Given Data / Assumptions:

• The wireless network uses 802.11b/g in a basic service set (BSS) with a single access point.
• The client has an 802.11b/g compatible wireless card.
• The access point client section shows no associated or active wireless LAN clients.
• The question asks for the most likely configuration error on the client that prevents association.

Concept / Approach:
The client must first discover the wireless network and then associate at Layer 2 before any IP configuration is relevant. Discovery and association rely on the service set identifier (SSID), security settings, and radio parameters. In most environments, the client scans the available channels automatically, so mismatched manual channel configuration is less common. An incorrect IP address or default gateway will not prevent association and therefore will still allow the access point to list the client as associated. In contrast, if the SSID on the client does not match the SSID that the access point is advertising, the client will not join that BSS at all, and the access point will show no associated client.

Step-by-Step Solution:
1. For a client to appear in the access point client list, it must complete the 802.11 association process at Layer 2.2. The client must send probe or association requests that include the SSID of the network it wants to join.3. The access point must be advertising the same SSID for the client to recognize and select that BSS.4. If the SSID configured on the client does not match the access point SSID, the client will never successfully associate with that access point.5. Because association never completes, the access point client table shows no active wireless LAN clients.

Verification / Alternative check:
An administrator can verify this by checking the client wireless profile and comparing the SSID string with the SSID configured on the access point. Correcting the SSID value or selecting the proper network from the list of available wireless networks typically immediately allows the client to associate and appear in the access point client list, confirming that the mismatch was the root cause.

Why Other Options Are Wrong:
Option A, an incorrect RF channel, is less likely because most modern clients automatically scan all 2.4 GHz channels to discover access points and do not require a manually configured channel. Option B, an IP address in the wrong subnet, does not prevent Layer 2 association and would still allow the client to appear in the access point table, although Layer 3 connectivity would fail. Option C, an incorrect pre-shared key, can prevent successful authentication, but in many implementations the client may still temporarily appear as an associating station before the key exchange fails, and the question highlights a configuration that cleanly prevents association. Option E, a wrong default gateway, affects routing beyond the local subnet but does not stop the 802.11 association process.

Common Pitfalls:
A frequent mistake is to troubleshoot IP addressing first when the problem is really that the client never joins the wireless LAN at all. Another pitfall is to overlook simple SSID spelling differences, including upper and lower case, hidden SSID settings, or accidental connection to a neighbor network with a similar name. Checking that the SSID configured on the client exactly matches the intended wireless network should be one of the first steps in any wireless troubleshooting process.

Final Answer:
The wireless client has the service set identifier (SSID) configured incorrectly.