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- CWSP-205
16.
Before an 802.11 client STA can pass traffic through the AP, which two of the following
must occur? (Choose two answers.)
- A.802.1X
- B.EAP
- C.Association
- D.Authentication
- E.WEP keys must match
- Answer & Explanation
- Report
Answer : [C, D]
Explanation :
Explanation :
| In order for a client to connect to the WLAN and pass data, the client must authenticate and associate to the AP. The other three choices could occur, but do not have to. |
17.
Which of the following is contained in a WEP-encrypted frame? (Choose all that apply.)
- A.IV in cleartext format
- B.IV in encrypted format
- C.Key identifier
- D.WEP key in encrypted format
- E.64-bit initialization vectorss
- Answer & Explanation
- Report
Answer : [A, C]
Explanation :
Explanation :
| When a WEP encrypted frame is created, the 24-bit Initialization Vector is included in the Layer 2 header of the 802.11 data frame in cleartext format. A Key Identifier is also included, indicating to the receiving computer which of the four potential WEP keys it should use to decrypt the frame. |
18.
128-bit WEP encryption uses a user-provided static key of what size?
- A.64 bits
- B.104 bits
- C.104 bytes
- D.128 bits
- E.128 bytes
- Answer & Explanation
- Report
Answer : [B]
Explanation :
Explanation :
| 128-bit WEP is known as WEP-104 in the 802.11-2012 standard. A 104-bit WEP key is provided by the user and the system adds to it the 24-bit Initialization Vector to equal 128 bits. |
19.
When SSID cloaking is enabled, which of the following occurs? (Choose all that apply.)
- A.The SSID field is set to null in the beacon frame.
- B.The SSID field is set to null in the probe request frame.
- C.The SSID field is set to null in the probe response frame.
- D.The AP stops transmitting beacon frames.
- E.The AP stops responding to probe request frames.
- Answer & Explanation
- Report
Answer : [A, C]
Explanation :
Explanation :
| When SSID cloaking, or Hidden SSID, is enabled, beacon management frames are still transmitted, but the SSID field is set to null. The probe response frame is almost identical to the beacon frame, and it too has the SSID field set to null. In any environment, the probe request frame may or may not contain a value for the SSID field, depending on whether the client knows the SSID of the network to which it is connecting. The AP cannot stop transmitting beacons because the frames contain additional information that is critical to the functioning of the network. When an AP receives a probe request frame, by default it will respond with a probe response frame. |
20.
Which technologies use the RC4 or ARC4 cipher? (Choose all that apply.)
- A.Static WEP
- B.Dynamic WEP
- C.PPTP
- D.L2TP
- E.MPPE
- Answer & Explanation
- Report
Answer : [A, B, E]
Explanation :
Explanation :
| WEP, whether it is statically configured or whether it changes periodically, uses this cipher to encrypt and decrypt frames. MPPE (Microsoft Point-to-Point Encryption) uses the ARC4 algorithm. TKIP (Temporal Key Integrity Protocol), which is covered in later chapters, also uses ARC4. |
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