Wireless networks allow computers to comunicate without the use of cables using IEEE 802.11 standards, also known as Wi-Fi. A connection is made from a device, which is usually a PC or a Laptop with a wireless network interface card (NIC), and an Access Point (AP), which acts as a bridge between the wireless stations and Distribution System (DS) or wired networks. An 802.11 wireless network adapter can operate in two modes, Ad-Hoc and Infrastructure. In infrastructure mode, all your traffic passes through a wireless ‘access point’. In Ad-hoc mode your computers talk directly to each other and do not need an access point. The table below shows the various standards.
|802.11a||54 mbps||100 ft||5 GHz|
|802.11b||11 mbps||300 ft||2.4 GHz|
|802.11g||54 mbps||300 ft||2.4 GHz|
|802.11n||540 mbps||600 ft||5 GHz and/or 2.4 GHz|
Authentication and Encryption :
- WEP – Wired Equivalent Privacy is a security encryption algorithm that is easily cracked. For this reason, it has been replaced by other technologies.
- WPA – The original WPA standard used TKIP, but was later replaced by WPA2 which uses a more secure AES-based algorithm. WPA uses a 256 bit key to encrypt data. This key may be entered either as a string of 64 hexadecimal digits, or as a passphrase of 8 to 63 characters. It is susceptible to brute force attacks when a weak passphrase is used.
- RADIUS – Remote Authentication Dial In User Service (RADIUS) is a networking protocol that provides centralized Authentication, Authorization, and Accounting (AAA) management for computers to connect and use a network service. RADIUS is often used by ISPs and enterprises to manage access to the Internet or internal networks, and wireless networks. Microsoft’s answer to corporate wireless security is the use of RADIUS authentication through its Internet Authentication Services (IAS) product.
- TKIP – Temporal Key Integrity Protocol was designed as a solution to replace WEP without requiring the replacement of legacy hardware. TKIP suffered from similar flaws as WEP and has been replaced by more secure encryption schemes.
**Source by wikipedia**
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