Articles
To read the articles in this section, simply click on the article title or read button on the far right (if visible).
Use the below filters to customise the number of articles displayed or search for specific title topics/keywords.
| Articles | |
|---|---|
| Read | |
| Read | |
| Read | |
|
Articles:
The DNS Protocol - Part 1: Introduction
| Read |
Suggested Articles:
Network Protocols
Trivial File Transport Protocol - TFTP
TFTP is a file transport protocol and its name suggests it's something close to the FTP protocol (File Transfer Protocol), which is true .. to a degr…
Network Fundamentals
Network Switches & Bridges
Network Switches are the evolution of Hubs and Repeaters, and enable the creation of networks by connecting multiple devices together. They are criti…
Subnetting
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 desir…
TCP - UDP Protocol Analysis
TCP Header Anaylsis - Section 6: TCP Options
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…
Featured Subcategories:
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
Follow Firewall.cx
Cisco Password Crack
Decrypt Cisco Type-7 Passwords on the fly!
VLAN Networks
VTP Protocol - In-Depth Analysis
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…
VLAN Networks
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 Netw…
VLAN Networks
VTP Pruning
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
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', 'Stati…
Routing
OSPF - Part 5: Analysis of OSPF Link State Update (LSU…
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 Routing Protocols
Distance Vector routing protocols use frequent broadcasts (255.255.255.255 or FF:FF:FF:FF) of their entire routing table every 30 sec. on all their interf…
Routing
Link State Routing Protocols
Link State routing protocols do not view networks in terms of adjacent routers and hop counts, but they build a comprehensive view of the overall network…
Routing
The IP Routing Process - Step-by-Step Analysis
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…
Cisco Routers
Troubleshooting PPP Internet Connection On A Cisco Rou…
The Point-to-Point Protocol is one of the most popular protocols around used by engineers, ISPs and companies around the globe for authentication of remot…
Windows Servers
How to Install and Configure SNMP for Windows Server 2…
Simple Network Management Protocol (SNMP) is a UDP protocol that uses port 161 to monitor and collect detailed information on any network device supportin…
Cisco Switches
Resolving Cisco Switch & Router ‘DHCP Server Pool Exha…
In previous articles, we showed how it is possible to configure a Cisco router or Catalyst switch to provide DHCP server services to network clients. Ever…
Cisco Switches
Cisco 4507R+E Layer 3 Installation: Redundant WS-X45-S…
It's no news that we here at Firewall.cx enjoy writing about our installations of Cisco equipment and especially devices that we don’t get to see and play…







