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Suggested Articles:
The OSI Model
The OSI Model: Layer 1 - Physical Layer
The Physical layer has two responsibilities: it sends bits and receives bits. Bits come only in values of 1 or 0. The Physical layer communicates dir…
Network Protocols
Introduction To Protocols
In the networking and communications area, a protocol is the formal specification that defines the procedures that must be followed when transmitting…
Domain Name System (DNS)
The DNS Protocol - Part 2: DNS Queries & Resoluti…
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 syste…
Network Address Translation - NAT
Network Address Translation (NAT) Concepts
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 i…
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Netflow Articles:
Netflow: Monitor Bandwidth & Network Utilization…
Monitoring network traffic & bandwidth usage via Netflow is mandatory for any type and size network. Gaining visibility into user traffic, applic…
Complete Guide to Netflow: How Netflow & its Comp…
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 Analyzer: Free Download, Step-by-Step Ins…
In our previous article we explained how a Netflow Analyzer can help you gain visibility into your user traffic, application traffic and data flows w…
Netflow vs SNMP. Two Different Approaches to Netw…
SNMP (Simple Network Management Protocol) and Netflow are both popular protocols with admins, prized for their ability to give visibility over the ne…
Wi-Fi Key Generator
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Cisco Password Crack
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VLAN Networks
Dynamic VLANs
Dynamic VLANs were introduced to grant the flexibility and complexity(!) that Static VLANs did not provide. Dynamic VLANs are quite rare because of their…
VLAN Networks
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 t…
VLAN Networks
VLAN InterSwitch Link (ISL) Protocol Analysis
Deciding whether to use ISL or IEEE 802.1q to power your trunk links can be quite confusing if you cannot identify the advantages and disadvantages of eac…
VLAN Networks
InterVLAN Routing - Routing between VLAN Networks
This article deals with the popular topic of InterVLAN routing, which is used to allow routing & communication between VLAN networks. Our article anal…
Routing
OSPF - Part 3: OSPF Adjacency & Neighbor Forming Proce…
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 examine…
Routing
OSPF - Part 1: Introduction, OSPF Packet Structure, OS…
Open Shortest Path First (OSPF) is a popular routing protocol developed for Internet Protocol (IP) networks by the Interior Gateway Protocol (IGP) working…
Routing
OSPF - Part 4: OSPF Neighbor States – OSPF Neighbor Fo…
This is the third article of our OSPF series which analyzes the different OSPF States routers go through during the OSPF discovery and neighbor forming pr…
Routing
Routing Information Protocol - RIP
Routing Information Protocol (RIP) is a distance-vector routing protocol that is commonly used in small to medium-sized networks. It is one of the o…
Virtualization & VM Backup
The Backup Bible. A Free Complete Guide to Disaster Re…
The Free Backup Bible Complete Edition written by backup expert and Microsoft MVP Eric Siron, is comprised of 200+ pages of actionable content divided int…
Network Protocol Analyzers
Advanced Network Protocol Analyzer Review: Colasoft Ca…
Firewall.cx has covered Colasoft Capsa several times in the past, but its constant improvements make it well worth revisiting. Since the last review, the…
Windows Servers
Windows Server Group Policy Link Enforcement, Inherita…
Our previous article explained what Group Policy Objects (GPO) are and showed how group policies can be configured to help control computers and users wit…
Virtualization & VM Backup
How to Fix VMware ESXi Virtual Machine 'Invalid Status'
In this article, we'll show you how to deal with VMs which are reported to have an Invalid Status as shown in the screenshot below. This is a common…







