In computer networking, MAC Filtering refers to a security access control method whereby the MAC address assigned to each network card is used to determine access to the network.
- MAC addresses are used in the local network while IP addresses can be used to identify network devices all around the world. Method 1: How to Find Your MAC Address in Windows 10 with Command Prompt.
- MAC Address or media access control address is a unique ID assigned to network interface cards (NICs). It is also known as a physical or hardware address. It identifies the hardware manufacturer and is used for network communication between devices in a network segment. MAC Address usually consists of six groups of two hexadecimal digits.
- Using Windows 10: Connect to a network. This method is only applicable if you are currently.
“MAC” stands for “Media Access Control,” this address is used to identify your device. The MAC address assigns to your network adapter. You need this to be able to use the Internet via LAN or WLAN. The 12-digit code is displayed in the hexadecimal system and is unique to your device. The first six digits indicate from which manufacturer.
MAC addresses are uniquely assigned to each card, so using MAC filtering on a network permits and denies network access to specific devices through the use of blacklists and whitelists. While the restriction of network access through the use of lists is straightforward, an individual person is not identified by a MAC address, rather a device only, so an authorized person will need to have a whitelist entry for each device that he or she would use to access the network.
While giving a network some additional protection, MAC filtering can be circumvented by using a packet analyzer to find a valid MAC and then using MAC spoofing to access the network using that address. MAC address filtering can be considered as security through obscurity because the effectiveness is based on 'the secrecy of the implementation or its components'.
Port security[edit]
Many devices that support MAC filtering do so on a device basis. Whitelisted MAC addresses are allowed through any port on the device and blacklisted MAC addresses are blocked on all ports. Other devices, such as Cisco Catalyst switches, support MAC filtering on a port-by-port basis. This is referred to as port security. Port security may be configured statically with a list, dynamically based on the first given number of addresses detected, or a combination of these two methods. When port security is configured, the default settings are to allow only one MAC address per port, and to shut down the port if the allowed number of addresses is exceeded.[1]
Wireless client isolation[edit]
MAC filtering is also used on enterprise wireless networks with multiple access points to create a private VLAN and prevent clients from communicating with each other. The access point can be configured to only allows clients to talk to the default gateway, but not other wireless clients.
See also[edit]
References[edit]
- ^'Configuring Port Security'. Cisco. Retrieved 14 November 2015.
External links[edit]
| Wikiversity has learning resources about Port security |
What Is a Message Authentication Code?
A message authentication code(MAC), or tag, is a security code that is typed in by the user of a computer to access accounts or portals. This code is attached to the message or request sent by the user. Message authentication codes (MACs) attached to the message must be recognized by the receiving system in order to grant the user access.
Understanding Message Authentication Code (MAC)
Message authentication codes(MACs) are commonly used in electronic funds transfers (EFTs) to maintain information integrity. They confirm that a message is authentic; that it really does come, in other words, from the stated sender, and hasn’t undergone any changes en route. A verifier who also possesses the key can use it to identify changes to the content of the message in question.
Message authentication codes are usually required to access any kind of financial account. Banks, brokerage firms, trust companies, and any other deposit, investment, or insurance company that offers online access can employ these codes. They are a vital component of financial cryptography.
Algorithms Used to Generate MACs
Three algorithms typically comprise a MAC: a key generation algorithm, a signing algorithm and a verifying algorithm. The key generation algorithm chooses a key at random. The signing algorithm sends a tag when given the key and the message. The verifying algorithm is used to verify the authenticity of the message when given the key and tag; it will return a message of accepted if the message and tag are authentic and unaltered, but otherwise, it will return a message of rejected.
For example, the sender sends a message, such as an EFT, through the MAC algorithm, which generates a key and attaches a MAC data tag to the message. The recipient gets the message, runs it back through the MAC algorithm with the same key, and gets a second data tag. He or she will then compare this MAC data tag with the first one attached to the message when it was transmitted. If the code is the same at both ends, the recipient can safely assume that the data integrity of the message is intact. If not, however, it means that the message was altered, tampered with or forged.
However, the message itself should contain some data that ensures that this message can only be sent once. For example, a one-time MAC, timestamp or sequence number could be used to guarantee that the message can only be sent once. Otherwise, the system could be vulnerable to a replay attack, in which an attacker intercepts the message after it has been decoded and retransmits it at a later time, replicating the original results and infiltrating the system.
Message Integrity Codes (MICs)
Sample Mac Address
Valid Mac Address
Sometimes, the term message integrity code(MIC) will be used instead of MAC. This is most often done in the communications industry, where MACtraditionally means media access control address(MAC address). However, MIC can also be used to refer to message digest, which does not use secret keys in the same manner as a MAC, and cannot offer the same level of security without further encryption.