Skip to main content

Network Fundamentals: Top Picks

Network Fundamentals
Content switches (also sometimes called application switches) is a class of network device that is becoming increasingly common in medium to large si…
Network Fundamentals
A MAC address, or Media Access Control address, is a unique identifier assigned to a network interface controller (NIC) for use as a network addres…
Network Fundamentals
Measuring network performance has always been a difficult and unclear task, mainly because most engineers and administrators are unsure which approac…
Network Fundamentals
Next-generation firewalls (NGFWs) and DMZ zones are two critical components of network security that work hand in hand to protect an organization's n…

Featured Subcategories:

Netflow Articles:

Netflow
Monitoring network traffic & bandwidth usage via Netflow is mandatory for any type and size network. Gaining visibility into user traffic, applic…
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
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
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…

Network Protocols:

Domain Name System (DNS)
This section will deal with the analysis of the DNS packets by examining how DNS messages are formatted and the options and variables they contain. T…
TCP - UDP Protocol Analysis
This article covers the UDP protocol. We examine the structure of the UDP header, the protocols that use UDP as a transport plus a lot more. Some co…
TCP - UDP Protocol Analysis
As previously mentioned on a number of occasions, TCP is one of the two protocols that lives at the Transport layer and is used to carry data from on…
Subnetting
Routing and Communication between subnets is the main topic here. This article analyses communications between subnets. We provide examples on differ…
TCP - UDP Protocol Analysis
This section contains one of the most well-known fields in the TCP header, the Source and Destination port numbers. These fields are used to specify…
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
The TCP Options (MSS, Window Scaling, Selective Acknowledgements, Timestamps, Nop) are located at the end of the TCP Header which is also why they ar…
Supernetting & CIDR
This articles build upon our previous pages covering  what is Supernetting (Route Summarization) & How Supernets Work and Supernetting In-De…

STP/ICMP Protocols:

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…
ICMP Protocol
The ICMP - Time Exceeded message is one which is usually created by gateways or routers. In order to fully understand this ICMP message, you must be…

All-in-one protection for Microsoft 365

All-in-one protection for Microsoft 365

FREE Hyper-V & VMware Backup

FREE Hyper-V & VMware Backup

Enterprise-Class Cloud & Network Monitoring

Enterprise Class Cloud & Network Monitoring - 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!

Bandwidth Monitor

Zoho Netflow Analyzer Free Download

Free PatchManager

Free PatchManager

Security Podcast

Hornet-Security-The-Swarm-Podcast

Firewall Analyzer

zoho firewall analyzer


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…
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
While the VLAN Tagging article briefly covered the IEEE 802.1q protocol this article will continue building upon it by further analyzing the IEEE 802.1q T…
VLAN Networks
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…

Routing
We are going to analyse what happens when routing occurs on a network (IP routing process). When I was new to the networking area, I thought that all you…
Routing
Enhanced Interior Gateway Routing Protocol (EIGRP), similar to IGRP, is a Cisco proprietary routing protocol that is used to exchange routing information…
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
Open Shortest Path First (OSPF) is a popular routing protocol developed for Internet Protocol (IP) networks by the Interior Gateway Protocol (IGP) working…

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…
Network Address Translation - NAT
NAT Overload is the most common NAT method used throughout all networks that connect to the Internet. This is because of the way it functions and the limi…
Network Address Translation - NAT
Dynamic NAT is the second NAT mode we're going to talk about. Dynamic NAT, like Static NAT, is not that common in smaller networks but you'll find it used…