OSI Network Model
The OSI model was developed years ago as a reference for network protocol and application designers to build their products with an open standard. That would promote a standard for developing network devices, interfaces, applications and services that would work together. It is a model rather than a specification since it defines layers and services for those layers and how each layer works with the layer above and below it. More ...
The OSI Presentation Layer
At this layer applications communicate on a format for exchanging data. The Session layer provides character set conversion and formats the data. It performs encryption and decryption, compression and decompression. More ...
Protocol Suites
Network protocols define rules for handling data and communicating in a particular networking environment. Individual protocols operate at specific layers in the OSI reference model. A protocol suite is a group of protocols designed to work together. More ...
Network Operating Systems
The purpose of a network is to permit users share resources located on other computers and to share peripheral devices such as printers. A network operating system (NOS) is specialized systems software designed to provide networking functionality. More ...
SYN-ACK Handshake to Establish a TCP Connection
TCP uses a SYN-ACK handshake to establish a connection. Three messages are required to establish a TCP connection between two hosts. More ...
A Simple Description of the IPv6 Header and Datagram
This article provides a simple description of the IPv6 header and datagram without a lot referring back to IPv4. More ...
Integration of IPv6 with IPv4
Almost all networks use IPv4. The question is how to move them over to IPv6 while allowing them to keep the networks they currently have operating. There are three methods. More ...
Virtual Local Area Networks (VLANs)
A Virtual LAN (VLAN) is a subgroup within a local network. VLANs make it easy for network administrators to separate a single switched network into subnetworks to match the functional and security requirements of their network without having to make major changes in the existing network infrastructure. More ...
TCP/IP Protocol Suite
A good portion of the knowledge required to be a network technician relates to the TCP/IP protocol suite. This article describes the most important protocols in the TCP/IP protocol suite. Many other less frequently used protocols exist. More ...
IPv6 Address Types and Scopes
An IPv6 addresses have a size of 128 bits have three types, unicast, multicast, and anycast. Unicast addresses are for a one-to-one communication. Multicast addresses are for a one-to-many communication. Anycast addresses are for one node to nearest node of multiple nodes communication. More ...
IPv6 Prefix Length Notation
In IPv4, the prefix (or network portion) of the address can be identified by a dotted-decimal netmask, commonly referred to as a subnet mask. IPv6 address prefixes can be represented much the same way that IPv4 address prefixes are written in CIDR notation. More ...
What Are Private IP Addresses?
Normally you have to be assigned an IP address, or a group of IP addresses by a Regional Internet Registry. However, if you just need IP addresses for an internal network that will not be routed to the Internet, you can select from blocks of IP addresses reserved as Private IP addresses. More ...
IPv6 Global Unicast Addresses
Global unicast addresses (GUAs) are globally routable and reachable in the IPv6 Internet; they are equivalent to public IPv4 addresses. GUA addresses are also known as aggregatable global unicast addresses. More ...
TCP/IP Utilities
TCP/IP comes with a set of command line utilities that a network technician can use to manage and troubleshoot a network. PING is used to test the ability of two hosts on a network to communicate. More ...
IPv4 Address Classes
Originally, IP network numbers were defined with rigid boundaries and grouped into address classes. Even though address classes was created to facilitate efficient use of the IPv4 address space, because of its rigidity it has been abandoned for more flexible classless addressing. More ...
