Tema 4.2 - Wifi advanced

In an 802.11 based communication, the 4 address fields available are used when:

• An access point sends a frame using WDS.

• A station sends a frame to an access point.

• An access point sends a frame to a station.

• None of the former.

The main limitations of mesh topologies under 802.11 (using 1 radio interface) are:

• All APs must use the same channel and the same shared key for encryption.

• All APs must use the same channel and encryption cannot be used.

• All APs must use different channels and encryption cannot be used.

• None of the former.

If 2 Access Points are connected to each other using WDS, the throughput between them will be maximized when:

• Both Access Points act as Repeaters.

• Both Access Points act as Bridges.

• One Access Point acts as a Repeater and the other one as a Bridge.

• It does not matter whether access points are acting as repeaters or bridges.

The encryption algorithm used by WEP is:

• MD5

• RC4

• AES

• A combination of the 3 previous ones.

The WEP algorithm allows defining:

• One key per user.

• Four keys per user.

• One key for all the users.

• Four keys for all the users.

The main problem of WEP (excluding the authentication) is:

• The size of the encryption key.

• The number of keys available.

• The IV is small and used in an inadequate manner.

• Using the RC4 algorithm.

To improve security when using WEP it is recommendable to:

• Use Open System authentication and not encrypting user data.

• Use Shared Key authentication and not encrypting user data.

• Use Open System authentication and encrypt user data using the shared key(s).

• Use Shared Key authentication and encrypt user data using the shared key(s).

In WEP, which of the following fields are encrypted along with user data:

• IV and Key number.

• 802.11 header.

• ICV.

• None of the former.

The main common element between WPA and WPA2 is:

• The authentication mechanism.

• The protocol used for data encryption.

• The protocol used to guarantee integrity.

• None of the above.

In Radius-based authentication, the key that allows managing trust between client and server is:

• MSK.

• PMK.

• PTK.

• GMK.