For example, to bypass the MAC address filtering on firewall or router. There are many reasons or possibilities that an user may want to change the MAC address or a network adapter, which also known as MAC spoofing. MAC address thus forms the basis of most of the layer 2 networking upon which higher OSI Layer protocols are built to produce complex, functioning networks.
Content of ARP table on each computer can be viewed by typing arp -a in Windows or arp in Linux. After translated (or when a host on LAN sends its MAC address to another machine which does not configured not to accept unrequested ARP replies on the network for preemptive caching), MAC address is cached on source PC ARP table for later use. In practical usage, layer 2 MAC address is converted from layer 3 protocol addresses such as Internet Protocol (IP address) by ARP (Address Resolution Protocol), which then allowed each host to be uniquely identified and frames to be marked for specific hosts on broadcast networks, such as Ethernet. In operating system, MAC address is often represented in 12-digit hexadecimal number.
As such, all network cards, whether it’s of Ethernet NIC, Gigabit Ethernet NIC or wireless 802.11a/b/g/n/ac WiFi or HiperLAN adapter, should have different MAC addresses, which also known as Ethernet Hardware Address (EHA) or adapter address. MAC address (Media Access Control address) is a quasi-unique identifier consists of a six byte number that attached to most network adapter card or network interface card (NIC).
0 kommentar(er)
