Active Directory : How Objects Are Stored and Identified
Data stored in Active Directory is presented to the user in a hierarchical fashion. There are two types of objects: containers and non-containers. The most common type of container in Active Directory is an OU (Organizational Unit). Non-container objects are also known as leaf nodes. 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 ...
Ports and Sockets
Data transmitted over the Internet carries a 32-bit IP address that identifies its destination computer and a 16-bit number that identifies a port on that computer. The combination of the IP address and the port number is called a socket. A pair of sockets, one on the sending computer and one on the receiving computer uniquely identifies a specific connection on the Internet. 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 ...
Video - The Upper Layers 5 Through 7 of the OSI Networking Model
In this video by Kevin Wallace you learn about Layers 5 Through 7 of the OSI networking model. More ...
Network Gateways
When networks with different protocols, such as Ethernet and Token Ring need to be connected together, this requires reconstruction of the data packets. To do this, information from above the network layer is required. A gateway is a device that can function at all seven layers of the OSI model. More ...
PoE (Power Over Ethernet)
Say you want to mount a wireless access point (AP) on the ceiling. Although no electrical outlet is available, a switch feature called Power over Ethernet (PoE) IEEE 802.3at standard offers as much as 32.4W of power over a UTP cable. More ...
Network Routing Protocols - IGRP, EIGRP, OSPF, ISIS, BGP
The purpose of routing protocols is to learn of available routes on the network and make routing decisions. There are two primary routing protocol types; link state and distance vector. Some of the most common routing protocols include RIP, IGRP, EIGRP, OSPF, IS-IS and BGP. More ...
The OSI Physical Layer
The Physical layer (OSI layer 1) deals with the mechanical and electrical specifications of the network hardware. Layer 1 specifications define connectors, pin-outs, signal voltages, and related software. More ...
Representation of IPv6 Addresses
IPv6 addresses are 128 bits in length and written as a string of hexadecimal digits. At first glance, these addresses can look overwhelming. RFC 2373 and RFC 5952 provide two helpful rules for reducing the notation involved in the standard format. 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 ...
DSL (Digital Subscriber Line)
DSL (Digital Subscriber Line) is a technology used to transmit digital data over telephone lines. DSL service can be transmitted simultaneously with voice band telephone service on the same line because DSL uses a much higher frequency that rides on top of the low 3400 Hz voiceband. More ...
OSI Transport Layer
The Transport layer (OSI layer 4) uses connection-oriented protocols to provide a reliable end-to-end connection between the source computer and the destination computer. Transmission Control Protocol (TCP) is a transport layer protocol. 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 ...
Comparison of the Layers of the OSI and TCP/IP Models
The TCP/IP protocol suite was developed by DARPA in the early 1970s. The OSI networking model was developed in Europe in 1986. This article compares the two networking standards. More ...
