CWS Wireless Security & Troubleshooting Techniques 5

Question 1

A CWS technician configures a captive portal for a guest WLAN. After connecting, guests receive an IP but are never redirected to the portal page. What is the MOST likely cause?

Accepted Answer

DNS not resolving hostnames so the HTTP redirect cannot be triggered

Answer

Captive portals rely on intercepting HTTP requests, which requires DNS resolution to succeed first; if DNS fails, browsers cannot make the initial request that triggers the redirect.

Question 2

Which metric BEST indicates whether a wireless client will experience high data rates: RSSI alone or SNR?

Accepted Answer

SNR, because throughput depends on signal quality relative to noise, not just signal strength

Answer

SNR (Signal-to-Noise Ratio) accounts for both signal strength and background noise; a high RSSI in a noisy environment can still result in poor throughput.

Question 3

What is the role of the 'pairwise master key' (PMK) in the WPA2 four-way handshake?

Accepted Answer

It is derived from the PSK or EAP authentication and used to generate the PTK

Answer

The PMK is the root key material from which the Pairwise Transient Key (PTK) is derived during the four-way handshake; it is never sent over the air.

Question 4

A user reports they can connect to the WLAN and browse the internet, but cannot reach internal corporate servers. The WLAN has separate guest and employee SSIDs on different VLANs. What is the MOST likely issue?

Accepted Answer

The user is connected to the guest SSID/VLAN instead of the employee SSID/VLAN

Answer

Guest VLANs typically only allow internet access and are firewall-blocked from internal resources; the user likely connected to the wrong SSID.

Question 5

During a wireless security audit, the auditor discovers the AP is using TKIP instead of CCMP. What risk does this introduce?

Accepted Answer

Vulnerability to known TKIP attacks such as the Beck-Tews attack, and lower cryptographic strength than AES-CCMP

Answer

TKIP was a stopgap replacement for WEP and has known vulnerabilities; CCMP (AES) is the current standard and provides significantly stronger protection.

(CWS) Certified Wireless Specialist Practice Test

(CWS) Certified Wireless Specialist Practice Test

CWS Wireless Security & Troubleshooting Techniques 5