SMC Networks 2.4GHz/5GHz manual 115

Models: 2.4GHz/5GHz

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Wireless Interface Commands

Command Usage

WPA enables the access point to support different unicast encryption keys for each client. However, the global encryption key for multicast and broadcast traffic must be the same for all clients. This command sets the encryption type that is supported by all clients.

If any clients supported by the access point are not WPA enabled, the multicast-cipher algorithm must be set to WEP.

WEP is the first generation security protocol used to encrypt data crossing the wireless medium using a fairly short key. Communicating devices must use the same WEP key to encrypt and decrypt radio signals. WEP has many security flaws, and is not recommended for transmitting highly sensitive data.

TKIP provides data encryption enhancements including per-packet key hashing (i.e., changing the encryption key on each packet), a message integrity check, an extended initialization vector with sequencing rules, and a re-keying mechanism.

TKIP defends against attacks on WEP in which the unencrypted initialization vector in encrypted packets is used to calculate the WEP key. TKIP changes the encryption key on each packet, and rotates not just the unicast keys, but the broadcast keys as well. TKIP is a replacement for WEP that removes the predictability that intruders relied on to determine the WEP key.

AES has been designated by the National Institute of Standards and Technology as the successor to the Data Encryption Standard (DES) encryption algorithm, and will be used by the U.S. government for encrypting all sensitive, nonclassified information. Because of its strength, and resistance to attack, AES is also being incorporated as part of the 802.11 standard.

Example

AP(if-wireless g)#multicast-cipher TKIP

AP(if-wireless g)#

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Page 285
Image 285
SMC Networks 2.4GHz/5GHz manual 115