Internet Protocol versions IPv4, IPv5 and IPv6
Internet Protocol is the part of the TCP/IP protocol that is responsible for addressing packets. IPv4 uses a 32-bit address IPv6 uses a 128-bit address. This article describes how IPv4 are converted to IPv6 addresses. More ...
Dynamic Host Configuration Protocol (DHCP) Explained
In the early days of TCP/IP each device on a network had stored on its hard disk a configuration file that an administrator used to manually assign a static IP address. Today a network administrator is no longer required to maintain an IP and MAC address configuration file a server. Every device on a network is automatically assigned a unique IP address by Dynamic Host Configuration Protocol (DHCP). More ...
Session Border Controllers - More Than Just a Voice Firewall
The migration from Time-Division Multiplexing to the more flexible IP based SIP networks brought an unexpected security challenge. Session Border Controllers focused primarily on SIP and H.323 session security. More ...
Evolution of the Microsoft NOS (Active Directory)
A Network operating system (NOS0) is a networked environment in which resources, such as users, groups, and computers are stored in a central repository. Microsoft's first integrated NOS environment became available in 1990 with the release of Windows NT 3.0. More ...
Looking at the OSI 7 Layer Reference Model
The OSI (Open Systems Interconnection) model is a 7 layer reference model for how applications can communicate over a network. Don't confuse The OSI model with TCP/IP Protocol which has 4 layers and is the actual architecture used for networking. More ...
Network Cabling and Components
Although the power and sophistication of networking protocols and software is impressive, a network could not operate without physical cable and components. Even a wireless network needs physical components such as access points. More ...
The OSI Application Layer
This layer provides the interface between applications and the Network Operating System (NOS). The Application layer provides network services and applications such as HTTP, FTP, TELNET and SMP. More ...
IPv6 Payload Length Field and Jumbograms
The IPv6 Payload Length field is a 16-bit field that indicates the length in bytes of just the payload following the main IPv6 header, it does not include the main IPv6 header. If the IPv6 packet has one or more extension headers, they are included in the number of bytes contained in the Payload Length field. More ...
Internet Security and VPN Network Design
This article discusses some essential technical concepts associated with a VPN. A Virtual Private Network (VPN) integrates remote employees, company offices, and business partners using the Internet and secures encrypted tunnels between locations. More ...
IP version 6 (IPv6) Advantages and Implementation
The Internet has, to all intents and purposes, run out of public IP version 4 addresses. The solution to this issue is new IP version 6. This would require a parallel IPv6 based Internet to be running until all IPv4 connections have been converted. More ...
IP Addressing and Subnetting
Today, many different kinds of devices can communicate on a network. A network device might be a computer, a router, a printer, or any number of unusual devices. Every device on a network that uses the Internet protocol (IP) needs a unique IP address. More ...
IGRP (Interior Gateway Routing Protocol)
IGRP (Interior Gateway Routing Protocol) is a routing protocol like RIP, however, it scales better than RIP because it uses a sophisticated metric based on bandwidth and delay, and has other advantages. More ...
Remote Control Protocols
Remote control protocols like Remote Desktop Protocol (RDP), Secure Shell (SSH), and Citrix Independent Computing Architecture (ICA), allow a system to access another system and transfer the user interface, keystrokes, and mouse movements between syatems as if you were actually sitting at the other syatem. 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 ...
Network Switches
A bridge or router may be referred to as a switch because it uses information in the data packet to choose a path from one network segment to another. A bridge may be referred to as a layer 2 switch because it uses information from layer 2, the Data Link layer of the OSI model. More ...
