網路原理(一) Section 5.2

burned-in address (BIA)
The MAC address is often referred to as a burned-in address (BIA) because, historically, this address is burned into ROM (Read-Only Memory) on the NIC.

ipconfig /all command
n a Windows host, the ipconfig /all command can be used to identify the MAC address of an Ethernet adapter.

ifconfig command
On a MAC or Linux host, the ifconfig command is used.

Unicast MAC Address
In Ethernet, different MAC addresses are used for Layer 2 unicast, broadcast, and multicast communications.  A unicast MAC address is the unique address used when a frame is sent from a single transmitting device to a single destination device.

Broadcast MAC Address
A broadcast packet contains a destination IPv4 address that has all ones (1s) in the host portion. This numbering in the address means that all hosts on that local network (broadcast domain) will receive and process the packet.

Multicast MAC Address
Multicast addresses allow a source device to send a packet to a group of devices. 

Content Addressable Memory (CAM)
The MAC address table is sometimes referred to as a content addressable memory (CAM) table. While the term CAM table is fairly common, for the purposes of this course, we will refer to it as a MAC address table.

Store-and-forward
A store-and-forward switch receives the entire frame, and computes the CRC.  If the CRC is valid, the switch looks up the destination address, which determines the outgoing interface.  The frame is then forwarded out the correct port.

Cut-through
A cut-through switch forwards the frame before it is entirely received.  At a minimum, the destination address of the frame must be read before the frame can be forwarded.

Fast-forward switching
Fast-forward switching offers the lowest level of latency. Fast-forward switching immediately forwards a packet after reading the destination address.

Fragment-free switching
In fragment-free switching, the switch stores the first 64 bytes of the frame before forwarding. Fragment-free switching can be viewed as a compromise between store-and-forward switching and fast-forward switching. 

Port-based Memory Buffering
In port-based memory buffering, frames are stored in queues that are linked to specific incoming and outgoing ports.

Shared Memory Buffering
Shared memory buffering deposits all frames into a common memory buffer that all the ports on the switch share. The amount of buffer memory required by a port is dynamically allocated. 

Half-duplex
半雙工（half-duplex）的系統允許二台裝置之間的雙向資料傳輸，但不能同時進行。因此同一時間只允許一裝置傳送資料，若另一裝置要傳送資料，需等原來傳送資料的裝置傳送完成後再處理。

Full-duplex
全雙工（full-duplex）的系統允許二台裝置間同時進行雙向資料傳輸。一般的電話、手機就是全雙工的系統，因為在講話時同時也可以聽到對方的聲音。 

Auto-MDIX
Most switch devices now support the mdix auto interface configuration command in the CLI to enable the automatic medium-dependent interface crossover (auto-MDIX) feature. 

Address Resolution Protocol (ARP)
位址解析協定 是通過解析網路層位址來找尋資料鏈路層位址的一個在網路協定包中極其重要的網路傳輸協定。