Cisco CCNA WLAN Architectures and Concepts 3 — Questions and Answers
Question 1: A network engineer configures a WLC to use local mode for APs in the headquarters building. What is a key characteristic of local mode?
- Client traffic is switched locally at the AP without reaching the WLC
- All client data is tunneled through CAPWAP to the WLC for centralized switching (Correct answer)
- APs operate autonomously without any WLC dependency
- Client traffic bypasses the WLC and goes directly to the router
Correct answer: All client data is tunneled through CAPWAP to the WLC for centralized switching
In local mode, all client data frames are encapsulated in CAPWAP tunnels and sent to the WLC, which then forwards them to the appropriate network.
Question 2: What is the primary role of a WLAN Distribution System (DS)?
- To provide wireless connectivity between client devices
- To interconnect multiple BSSs to form an ESS via a wired backbone (Correct answer)
- To encrypt traffic between APs and clients
- To manage IP address assignment for wireless clients
Correct answer: To interconnect multiple BSSs to form an ESS via a wired backbone
The Distribution System interconnects multiple access points (BSSs) using a wired backbone, forming an Extended Service Set (ESS) for seamless roaming.
Question 3: Which 802.11 band characteristic makes 5 GHz preferable to 2.4 GHz in dense environments?
- 5 GHz has greater range and penetrates walls better
- 5 GHz has more non-overlapping channels and typically less interference (Correct answer)
- 5 GHz is backward compatible with all 802.11b devices
- 5 GHz requires less transmit power for the same coverage area
Correct answer: 5 GHz has more non-overlapping channels and typically less interference
The 5 GHz band offers up to 24 non-overlapping channels (in the US) compared to only 3 in 2.4 GHz, reducing co-channel interference in dense deployments.
Question 4: In a Cisco WLC deployment, what happens during the CAPWAP discovery process when an AP first boots?
- The AP sends a DHCP request with a WLC IP option and waits for a unicast response
- The AP broadcasts/multicasts a CAPWAP Discovery Request and the WLC responds with a Discovery Response (Correct answer)
- The AP queries a RADIUS server for the WLC IP address
- The AP scans all channels to find a beacon from the WLC
Correct answer: The AP broadcasts/multicasts a CAPWAP Discovery Request and the WLC responds with a Discovery Response
An AP sends CAPWAP Discovery Requests via broadcast, multicast, or preconfigured unicast to locate a WLC, which replies with a Discovery Response.
Question 5: Which wireless security protocol replaced TKIP with CCMP/AES as its mandatory encryption method?
- WEP
- WPA (Wi-Fi Protected Access)
- WPA2 (Correct answer)
- 802.1X only
Correct answer: WPA2
WPA2 mandates CCMP with AES encryption, replacing the weaker TKIP used in WPA and making it significantly more secure.
Question 6: What is the function of the 802.11 Probe Request frame?
- Sent by an AP to announce its presence on a channel
- Sent by a client to actively discover available wireless networks (Correct answer)
- Sent by a WLC to verify AP connectivity
- Sent by a client to confirm successful association with an AP
Correct answer: Sent by a client to actively discover available wireless networks
A Probe Request is sent by wireless clients to actively scan for available SSIDs, either broadcasting to find all networks or targeting a specific SSID.
Question 7: In a Cisco WLC environment, which interface type is used to manage the WLC itself and is required for AP CAPWAP connections?
- Dynamic Interface
- AP-Manager Interface
- Management Interface (Correct answer)
- Virtual Interface
Correct answer: Management Interface
The Management Interface is the primary interface used for WLC administration, AP CAPWAP tunnel termination, and network management traffic.
Cisco CCNA WLAN Architectures and Concepts 3
A network engineer configures a WLC to use local mode for APs in the headquarters building.
What is a key characteristic of local mode?