Network Fundamentals: Top Picks
Need for Speed – The Data Tsunami & Advancement...
A long-long time ago (not long ago in earth time) 100 Mbps was THE technology. 100 Mbps uplinks bundled with ether-channel was the ultimate uplink ...
Introduction To Networking
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 ...
Hubs & Repeaters
Network hubs were once the primary method of interconnecting network devices to create a local area network (LAN). Hubs were inexpensive, easy to i...
Next-Gen Firewalls & Topologies. Designing & Bu...
Next-generation firewalls (NGFWs) and DMZ zones are two critical components of network security that work hand in hand to protect an organization's...
Featured Subcategories:
Netflow Articles:
Complete Guide to Netflow: How Netflow & its Co...
This article will cover the basics of Netflow, including its use cases, Netflow supported devices, Netflow history, and variants. We’ll also dive i...
NetFlow Analyzer: Free Download, Step-by-Step I...
In our previous article we explained how a Netflow Analyzer can help you gain visibility into your user traffic, application traffic and data flows...
Netflow vs SNMP. Two Different Approaches to Ne...
SNMP (Simple Network Management Protocol) and Netflow are both popular protocols with admins, prized for their ability to give visibility over the ...
Netflow: Monitor Bandwidth & Network Utilizatio...
Monitoring network traffic & bandwidth usage via Netflow is mandatory for any type and size network. Gaining visibility into user traffic, appl...
Network Protocols:
The DNS Protocol - Part 2: DNS Queries & Resolu...
This section will help you understand how the DNS queries work on the Internet and your home network. There are two ways to use the domain name sys...
Transmission Control Protocol - Part 4: In-Dept...
This article is an introduction to the 7-page TCP Header analysis section that follows. We briefly view each section of the TCP Header and then mov...
IP Subnet Calculator
This free online Subnet Calculator provides a fast and easy way to calculate all aspects of any IP Address and Subnet Mask. Simply enter your des...
Transmission Control Protocol - Part 1: Introdu...
Understanding how each protocol fits into the OSI Model is essential for any network engineer. This page analyses how TCP is classified as a 'trans...
IP Subnetting - Part 2: Subnet Masks & Their Ef...
There are a few different ways to approach subnetting and it can get confusing because of the complexity of some subnets and the flexibility they o...
TCP Header Anaylsis - Section 7: TCP Data Paylo...
Finally, the last page of our incredible TCP Analysis. As most of you would expect, this section is dedicated to the DATA section that follows the ...
IP Protocol - Part 1: Binary & The Internet Pro...
To understand the Internet Protocol, we need to learn and understand Binary. It is very important to know and understand Binary because part of the...
TCP Header Anaylsis - Section 4: TCP Flag Options
As we have seen in the previous pages, some TCP segments carry data while others are simple acknowledgements for previously received data. The popu...
STP/ICMP Protocols:
Spanning Tree Protocol – Part 3: Bridge ID, Pri...
In this article we will examine the Spanning Tree Bridge ID structure, explain why it has increments of 4096, how VLAN information is embedded (for...
ICMP Protocol - Part 1: Introduction
The Internet Control Message Protocol (ICMP), is a very popular protocol and actually part of an Internet Protocol (IP) implementation. Because IP ...
ICMP Protocol - Part 6: Redirect Messages
The ICMP - Redirect Message is always sent from a gateway to the host and the example below will illustrate when this is used.
Putting it simply (...
Spanning Tree Protocol – Part 2: Rapid STP Port...
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 b...
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VLAN Tagging - Understanding VLANs Ethernet Frames
We mentioned that Trunk Links are designed to pass frames (packets) from all VLANs, allowing us to connect multiple switches together and independently ...
The VLAN Concept - Introduction to VLANs
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 Ne...
Comparing Traditional Flat & VLAN Networks
Designing and building a network is not a simple job. VLANs are no exception to this rule, in fact they require a more sophisticated approach because of...
VLANs - Access & Trunk Links
If you've read our previous article The VLAN Concept - Introduction to VLANs then you should feel comfortable with terms such as 'VLAN', 'Sta...
Enhanced Interior Gateway Routing Protocol - EIGRP
Enhanced Interior Gateway Routing Protocol (EIGRP), similar to IGRP, is a Cisco proprietary routing protocol that is used to exchange routing informatio...
Introduction to Routing Protocols
Distance Vector, Link State RIP, IGRP, EIGRP, OSPF
Routing protocols were created for routers. These protocols have been designed to allow the exchan...
OSPF - Part 2: How OSPF Protocol Works & Basic Conce...
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 ...
OSPF - Part 3: OSPF Adjacency & Neighbor Forming Pro...
This is the thrid article of our 6-part OSPF series (see below) that describes how OSPF routers perform neighbor relationship and adjacency. We’ll exami...