Cisco - Networking Terminology

Networking Terminology: 

• Packet: A packet is, the most basic unit that is transferred over a network. When communicating over a network, packets are the envelopes that carry your data from one end point to the other.

• LAN: LAN stands for “local area network”. It refers to a network or a portion of a network that is not public. A home or office is an example of a LAN.

• WAN: WAN stands for “wide area network”. It means a network that is much more extensive than a LAN. While WAN is the relevant term to use to describe large, dispersed networks in general, it is usually meant to mean the internet, as a whole.

• Firewall: A firewall is a program that decides whether traffic coming into a server or going out should be allowed. A firewall usually works by creating rules for which type of traffic is acceptable on which ports. Generally, firewalls block ports that are not used by a specific application on a server.

• VPN: VPN stands for virtual private network. It is a means of connecting separate LANs through the internet, while maintaining privacy. This is used as a means of connecting remote systems as if they were on a local network, often for security reasons.

• Router: A router is a device that passes traffic back and forth. You likely have a home router. It’s that router’s job to pass outgoing traffic from your local devices to the Internet, and to pass incoming traffic from the Internet to your devices.

• DHCP: The dynamic host configuration protocol allows computers to automatically request and be assigned IP addresses and other network settings. For example, when you connect your laptop or smartphone to your Wi-Fi network, your device asks the router for an IP address using DHCP and the router assigns an IP address. This simplifies things — you don’t have to set up static IP addresses manually.

• Switch: Switches manage the flow of data across a network by transmitting a received network packet only to the one or more devices for which the packet is intended.