The Open System Interconnection (OIS) reference model is a template and using a network and its resources.
Application Layer: Responsible fro interacting with end users.
Presentation Layer: Responsible for the coding of data.
Session Layer: Responsible for maintaining communication sessions between computers.
Transport Layer: Responsible for breaking data into packets and properly transmitting it over the network.
Network Layer: Responsible for the logical implementation of the network.
Data Link Layer: Responsible for transmitting information on computers connected to the same local area network (LAN).
Physical Layer: Responsible for the physical operation of the network.
The two types of networks are:
Wide Area Networks: WANs connect systems over a large geographical area. Connectivity Options
Routers: is a device that connects two or more networks and selectively interchanges packets of data between them.
Border Routers: is a subject to direct attack from an outside source.
Internal Routers: can also provide enhanced features to your internal networks.
Network Address Translation: (NAT) is a method of IP address assignment that uses an alternate, public IP address to hide a system’s real IP address.
Local Area Networks: (LAN) provide network connectivity for computers located in the same geographical area. Ethernet Networks
LAN Devices: Hubs and Switches: Hubs are simple network devices. They contain a number of plugs (or ports) where you can connect Ethernet cables for different network system. Switch is a network device that connects network segments, creating a direct connection between a sending and receiving port.
Transmission Control Protocol/Internet Protocol (TCP/IP): A popular suite of protocols that operate at both the Network and the Transport layers of the OSI reference model.
IP Addresses are four-byte addresses that uniquely identify every device on the network.
Dynamic Host Configuration Protocol (DHCP): A