Skip to main content

Network Fundamentals: Top Picks

Network Fundamentals
Network Switches are the evolution of Hubs and Repeaters, and enable the creation of networks by connecting multiple devices together. They are criti…
Network Fundamentals
Multicast is a communication method used in computer networking where data is sent from a single sender to a group of destination devices. In this m…
Network Fundamentals
Power over Ethernet (PoE) was invented by PowerDsine back in 1997 and the first power injector (Midspan) was installed in 1998! Many manufacturespart…
Network Fundamentals
A network is simply a group of two or more Personal Computers linked together. Many types of networks exist, but the most common types of networks ar…

Featured Subcategories:

Netflow Articles:

Netflow
This article will cover the basics of Netflow, including its use cases, Netflow supported devices, Netflow history, and variants. We’ll also dive int…
Netflow
SNMP (Simple Network Management Protocol) and Netflow are both popular protocols with admins, prized for their ability to give visibility over the ne…
Netflow
Monitoring network traffic & bandwidth usage via Netflow is mandatory for any type and size network. Gaining visibility into user traffic, applic…
Netflow
In this article, we explore the core principles of bandwidth management and examine how modern network monitoring technologies can assist in maintain…

Network Protocols:

Subnetting
There is always that day when you are called upon to provide a solution to a network problem. The number of problems that can occur in a network are…
TCP - UDP Protocol Analysis
This page will closely examine the Sequence and Acknowledgement numbers. The very purpose of their existence is related directly to the fact that the…
TCP - UDP Protocol Analysis
Our fifth section contains some very interesting fields that are used by the TCP transport protocol. We see how TCP helps control how much data is tr…
Domain Name System (DNS)
The previous article covered the DNS Query message formats. In the article we analysed them in great detail and showed how various options are select…
Domain Name System (DNS)
If you ever wondered where DNS came from, this is your chance to find out ! The quick summary on DNS's history will also help you understand why DNS…
TCP - UDP Protocol Analysis
As we have seen in the previous pages, some TCP segments carry data while others are simple acknowledgements for previously received data. The popula…
Subnetting
When we subnet a network, we basically split it into smaller networks. For example, when a set of IP Addresses is given to a company, e.g 254 they mi…
Supernetting & CIDR
Our previous article served as an introduction to Supernetting, also known as Route Summarization. We covered the concept of Supernetting, how it wor…

STP/ICMP Protocols:

ICMP Protocol
As mentioned in the previous page, an Echo is simply what we networking engineers call a 'ping'. The Echo Reply is, as most would guess,  the 'p…
Spanning Tree Protocol (STP)
One of the most used terms in network is LAN (Local Area Network). It’s a form of network that we encounter in our daily lives, at home, at work, stu…
Spanning Tree Protocol (STP)
Spanning Tree Protocol, Rapid STP port costs and port states are an essential part of the STP algorithm that affect how STP decides to forward or blo…
ICMP Protocol
The 'ICMP Destination unreachable' message is quite interesting, because it doesn't actually contain one message, but infact six! This means that the…

Free eBook - Endpoint Security

Manageengine Free Ebook on Endpoint Security

Enterprise-Class Cloud & Network Monitoring

Enterprise Class Cloud & Network Monitoring - Free Download

Bandwidth Monitor

Zoho Netflow Analyzer Free Download

Wi-Fi Key Generator

Generate/Crack any
WEP, WPA, WPA2 Key!

Network and Server Monitoring

Network and Server Monitoring

Follow Firewall.cx

Cisco Password Crack

Decrypt Cisco Type-7 Passwords on the fly!

Decrypt Now!

Automated Patching Solution

Free PatchManager

Firewall Analyzer

zoho firewall analyzer


VLAN Networks
VTP (VLAN Trunking Protocol) pruning is a feature that is used in Cisco switches to reduce unnecessary traffic in VLAN (Virtual Local Area Network) trunks…
VLAN Networks
If you've read our previous article The VLAN Concept - Introduction to VLANs  then you should feel comfortable with terms such as 'VLAN', 'Stati…
VLAN Networks
We hear about them everywhere, vendors around the world are constantly trying to push them into every type of network and as a result, the Local Area Netw…
VLAN Networks
The invention of VLANs was very much welcomed by all engineers and administrators, allowing them to extend, redesign and segment their existing network wi…

Routing
This article explains how OSPF uses Link State Advertisement (LSA) to exchange information about the network topology between routers. When a router recei…
Routing
Distance Vector, Link State RIP, IGRP, EIGRP, OSPF Routing protocols were created for routers. These protocols have been designed to allow the exchange…
Routing
Our previous article explained the purpose of Link State Update (LSU) packets and examined the Link State Advertisement (LSA) information contained within…
Routing
This article covers basic OSPF concepts and operation. We explain how OSPF works, how OSPF tables are built on an OSPF-enabled router and their purpose (N…

Network Address Translation - NAT
Our previous article, Dynamic NAT - Part 1, covered the basic idea of Dynamic Network Address Translation. We are now going to take a closer look at the p…
Network Address Translation - NAT
Before we dive into the deep waters of NAT, we need to make sure we understand exactly what NAT does. So let me give you the background of NAT, why it's h…
Network Address Translation - NAT
In our previous article, Network Address Translation (NAT) Overload - Part 1, we explained what NAT Overload is and how it works. This page deals with the…
Network Address Translation - NAT
The previous page (Static NAT - Part 1) helped us understand what exactly happens with Static NAT and how it works, and we saw a few examples of how to us…