Networking
Network Introduction
A network is nothing two or more computers connected by a cable or a wireless radio connection so that they can exchange information. These computers are normally connected by a wire that's on a switch, the switch is normally connected to a patch panel in small and big businesses. Networks are designed to share files, resources and programs.
LAN stands for local area network. WAN stands for wide area network. MAN stands for metropolitan area network.
The network that contains the hard drives printers and other resources that are shared with network computers is a server. Any computer that is not a server is a client.
A node is a device that's connected to the network. A node is the same as a computer.
A packet is a message that is sent over the network from one node to another node. The packet includes the address of the node that sent the packet.
Networking
The internet protocol (IP) defines the format of IP addresses: four eight-bit numbers called octets who's decimal values rage from 0 to 255.
| Layers | Definition | |||
|---|---|---|---|---|
| Physical (1) | mechanical & electrical details of network components, this includes cables, connectors and network interfaces. | |||
| Data link (2) | how devices are identified on the network, typically MAC addresses. Switches operate at this layer. | |||
| Network (3) | handles the routing of data across networks. Routers operate here. | |||
| Transport (4) | provides the reliable delivery of packets. | |||
| Session (5) | establishes sessions between network applications. | |||
| Presentation (6) | converts data so that systems that use different data formats can exchange information. | |||
| Application (7) | allows applications to request network services. |
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