網路原理(一) Section 2.3 ***重要***

IPv4 address
網際協定版本4（英語：Internet Protocol version 4，IPv4），又稱網際網路通訊協定第四版，是網際協定開發過程中的第四個修訂版本。IP addresses can be assigned to both physical ports and virtual interfaces on devices.

Subnet mask
子網路遮罩，用來切割IP address，例如192.168.0.0/24，代表遮罩為255.255.255.0IPv4 subnet mask is a 32-bit value that separates the network portion of the address from the host portion. Coupled with the IPv4 address, the subnet mask determines which particular subnet the device is a member.

Default gateway
The default gateway address is the IP address of the router that the host will use to access remote networks, including the Internet. 

Physical ports
A connector or outlet on a networking device where the media is connected to an end device or another networking device.

Virtual interface
虛擬介面

copper
銅線

fiber optics
光纖

wireless
無線

ethernet
乙太網
Ethernet is the most common local area network (LAN) technology used today. Ethernet ports are found on end-user devices, switch devices, and other networking devices that can physically connect to the network using a cable.  

Local Area Network
區域網路

Layer 2 switch
Cisco IOS Layer 2 switches have physical ports for devices to connect. These ports do not support Layer 3 IP addresses.
Layer 3 addresses
IP address

Switch virtual interface (SVI) 
switches have one or more switch virtual interfaces (SVIs). These are virtual interfaces because there is no physical hardware on the device associated with it. An SVI is created in software.The virtual interface provides a means to remotely manage a switch over a network using IPv4. Each switch comes with one SVI appearing in the default configuration "out-of-the-box." The default SVI is interface VLAN1.

Dynamic Host Configuration Protocol (DHCP)
動態主機設定協定（英語：Dynamic Host Configuration Protocol，DHCP）是一個區域網路的網路協定，使用UDP協定工作，主要有兩個用途： 用於內部網路或網路服務供應商自動分配IP位址給用戶

Domain Name System (DNS)
The DNS server addresses are the IPv4 addresses of the Domain Name System (DNS) servers, which are used to translate IP addresses to domain names, such as www.cisco.com.

ipconfig command prompt
Windows cmd可以打的指令

interface vlan 1
To configure an SVI on a switch, use the interface vlan 1 global configuration command.