The following are different display formats:
以下是不同的顯示格式：
- 0000.0c43.2e080000.0c43.2e08
- 00:00:0c:43:2e:0800:00:0c:43:2e:08
- 00-00-0C-43-2E-0800-00-0C-43-2E-08
A MAC address is composed of 12 hexadecimal digits, which means it has 48 bits. There are two main components of a MAC address. The first 24 bits constitute the Organizationally Unique Identifier (OUI). The last 24 bits constitute the vendor-assigned, end-station address:
MAC 位址由 12 個十六進位數字組成，代表其長度為 48 位元。MAC 位址主要由兩部分組成：前 24 位元構成組織唯一識別碼（OUI），後 24 位元則構成由廠商指派的終端站台位址：
- 24-bit OUI: The OUI identifies the manufacturer of the NIC. The IEEE regulates the assignment of OUI numbers. Within the OUI, 2 bits have meaning only when used in the destination address field:24 位元 OUI：OUI 用來識別 NIC 的製造商，其分配由 IEEE 規範管理。在 OUI 中，有 2 個位元只有在用於目的地位址欄位時才有意義：
- Broadcast or multicast bit: When the least significant bit in the first octet of the MAC address is 1, it indicates to the receiving interface that the frame is destined for all (broadcast) or a group of (multicast) end stations on the LAN segment. This bit is referred to as the Individual/Group (I/G) address bit.廣播或群播位元：當 MAC 位址第一個位元組中最低位元為 1 時，代表對接收介面而言，這個框架的目的地為 LAN 網段上的所有終端裝置（廣播），或一群終端裝置（群播）。此位元稱為個別／群組（I/G）位址位元。
- Locally administered address bit: The second least significant bit of the first octet of the MAC address is referred to as a universally or locally (U/L) administered address bit. Normally, the combination of the OUI and a 24-bit station address is universally unique. However, if the address is modified locally, this bit should be set to 1.本地管理位址位元：MAC 位址第一個位元組中第二低的位元，稱為全域或本地（U/L）管理位址位元。一般情況下，OUI 與 24 位元站台位址的組合在全球是唯一的。但如果該位址經過本地修改，則此位元應設為 1。
- 24-bit, vendor-assigned, end-station address:This portion uniquely identifies the Ethernet hardware.24 位元，由廠商指派的終端站台位址：這部分用來唯一識別乙太網路硬體。
There are three types of communications: Unicast, Multicast, and Broadcast. Hence, there are also three types of MAC Addresses:
通訊有三種類型：單播、群播與廣播，因此 MAC 位址也對應有三種類型：
- Unicast MAC Address: A MAC Address that identifies only one NIC on the network and it is the Layer 2 destination of a Unicast transmission. 00:00:0c:43:2e:08 is an example of Unicast MAC Address.單播 MAC 位址：只識別網路上單一 NIC 的 MAC 位址，是單播傳輸的第 2 層目的地。00:00:0c:43:2e:08 即為單播 MAC 位址的範例。
- Broadcast MAC Address: A MAC address that identifies all the NICs in the Layer 2 domain. The Broadcast MAC Address format is FF:FF:FF:FF:FF:FF and it is the Layer 2 destination of a Broadcast transmission.廣播 MAC 位址：識別第 2 層網域中所有 NIC 的 MAC 位址，是廣播傳輸的第 2 層目的地。廣播 MAC 位址的格式為 FF:FF:FF:FF:FF:FF。
- Multicast MAC Address: A MAC address that identifies a group of NICs in the Layer 2 domain, and it is the Layer 2 destination of a Multicast transmission. The Multicast MAC Address always begins with 01:00:5E and the last 23 bits are calculated from the Multicast Group IP Address.群播 MAC 位址：識別第 2 層網域中一群 NIC 的 MAC 位址，是群播傳輸的第 2 層目的地。群播 MAC 位址一律以 01:00:5E 開頭，後 23 個位元則是由群播群組 IP 位址計算而得。
How many hexadecimal digits represent each MAC address?每個 MAC 位址由多少個十六進位數字表示？