A basic understanding of networking is important for anyone managing a server. Not only is it essential for getting your services online and running smoothly, but it also gives you the insight to diagnose problems.
BASIC NETWORKING
TERMINOLOGY
NETWORK LAYERS
Networking is often discussed in terms of topology in a horizontal way, between hosts, its implementation is layered in a vertical fashion throughout a computer or network.
The Open Systems Interconnect (OSI) model is a conceptual framework for understanding how data flows over a network. It’s a reference model which acts as a roadmap for what’s happening across and within a network.
This model defines 7 separate layers. The layers in this model are:
Presentation: The presentation layer is responsible for mapping resources and creating context.
Session: The session layer is a connection handler. It creates, maintains, and destroys connections between nodes in a persistent way.
Transport: The transport layer is responsible for handling the layers above it a reliable connection. In this context, reliable refers to the ability to verify that a piece of data was received intact at the other end of the connection.
Network: The network layer is used to route data between different nodes on the network. It uses addresses to be able to tell which computer to send information to.
Data Link: This layer is implemented as a method of establishing and maintaining reliable links between different nodes or devices on a network using existing physical connections.
Physical: The physical layer is responsible for handling the actual physical devices that are used to make a connection.
