Skip to main content

Network Fundamentals: Top Picks

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
Network topologies can take a bit of time to understand when you're all new to this kind of cool stuff, but it's very important to fully understand t…
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
Content switches (also sometimes called application switches) is a class of network device that is becoming increasingly common in medium to large si…

Featured Subcategories:

Netflow Articles:

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…
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
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…

Network Protocols:

IP Protocol
This article examines the Internet Protocol (IP) and its position within the OSI Model. We take a look at the IP Header and all fields contained with…
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
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 TC…
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
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…
Supernetting & CIDR
Supernetting is the opposite of of subnetting, and is also known as route aggregation or CIDR (Classless Inter-Domain Routing). Supernetting is a tec…
Domain Name System (DNS)
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…

STP/ICMP Protocols:

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 - Redirect Message is always sent from a gateway to the host and the example below will illustrate when this is used. Putting it simply (be…
ICMP Protocol
The Internet Control Message Protocol (ICMP), is a very popular protocol and actually part of an Internet Protocol (IP) implementation. Because IP wa…
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
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
We mentioned that Trunk Links are designed to pass frames (packets) from all VLANs, allowing us to connect multiple switches together and independently co…
VLAN Networks
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
The previous article introduced the VTP protocol, we examined how it can be used within a network, to help manage VLANs and ease the administrative overhe…

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
This article explains how OSPF uses Link State Advertisement (LSA) to exchange information about the network topology between routers. When a router recei…
Routing
Hybrid routing protocols are a combination of distance-vector and link-state routing protocols, and are used to provide a more efficient and scalabl…
Routing
Enhanced Interior Gateway Routing Protocol (EIGRP), similar to IGRP, is a Cisco proprietary routing protocol that is used to exchange routing information…

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
Static NAT (also called inbound mapping) is the first mode we're going to talk about and also happens to be the most uncommon between smaller networks. S…
Network Address Translation - NAT
After that simple and informative introduction to the NAT concept, it's time to find out more about how it works and this is where the NAT table comes in…
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…