Link Aggregation
If all ports on a switch are operating at the same speed, the ports most likely to experience congestion are ports connecting to another switch or router. To help alleviate congested links between switches, you can logically combine multiple physical connections into a single logical connection. 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 ...
Video - Introducing the OSI Model
This video by Kevin Wallace introduces the OSI networking model. More ...
The TCP/IP protocol Datagram Format
A datagram is the packet format defined by the Internet Protocol. A pictorial representation of an IP datagram shows the first five or six 32-bit words of the datagram are control information called the header. 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 ...
Major Protocols in the TCP/IP Suite
This is a chart of the layers of the TCP/IP Suite and the major protocols in each layer. As you move your mouse pointer over each protocol acronym, a brief description of the protocol appears. This is not a comprehensive list. More ...
Understanding IP Routing
The Transmission Control Protocol/Internet Protocol TCP/IP suite of protocols is the underlying technology for information exchange on the Internet. This essential reference shows you how to isolate and resolve common network failures and to sustain optimal network operation. 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 ...
The OSI Reference Model
No real world network operating systems conform exactly to the OSI model, but it is useful as a reference when describing existing systems. It is difficult to study network devices such as routers, switches, and gateways without using the model. 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 ...
NTP Server Systems - The Network Time Protocol
The Network Time Protocol (NTP) is utilized by NTP Server systems to distribute accurate time information to network time clients. The NTP protocol is widely used throughout the Internet to provide synchronization of computers and processes. This article discusses how NTP server systems utilize the Network Time Protocol to provide networks with an accurate reference of time. More ...
IPv4 Datagram Fields
If you are pursuing CompTIA Network+ certification, of if you're involved in network troubleshooting, it's important to understand the construction of an IP datagram. More ...
An Introduction to the Types of VPNs
There are three types of VPNs that provide users with the functionality described above and these fall within the two categories: computer-to-network VPNs and network-to-network VPNs. 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 ...
Free eBook: IPv6 Addressing
All the IPv4 addresses are quickly being used up. The conversion to IPv6 is now underway. In this free eBook, Aaron Balchunas describes IPv6 and how to configure it to work along side IPv4. Learn which protocols will need to be updated to work with IPv6. Learn how to configure IPv6. More ...
