Suggested Articles:
ICMP Protocol
ICMP Protocol - Part 4: Destination Unreachable M…
The 'ICMP Destination unreachable' message is quite interesting, because it doesn't actually contain one message, but infact six! This means that the…
The OSI Model
The OSI Model: Layer 5 - Session Layer
The Session layer is responsible for setting up, managing and then tearing down sessions between Presentation layer entities. The Session layer also…
Network Fundamentals
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 ar…
Ethernet Protocol, CSMA/CD, Collisions
802.3 Fast Ethernet (100 Mbit/Sec) Model
Here we see a logical drawing of the Fast Ethernet Data Link Layer sublayers. Data is passed down from the upper layers (such as TCP/IP or Novell Net…
Featured Subcategories:
Netflow Articles:
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…
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 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…
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…
Wi-Fi Key Generator
Follow Firewall.cx
Cisco Password Crack
Decrypt Cisco Type-7 Passwords on the fly!
VLAN Networks
Static VLANs
VLANs are usually created by the network administrator, assigning each port of every switch to a VLAN. Depending on the network infrastructure and securit…
VLAN Networks
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 co…
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
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
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 exchange…
Routing
OSPF - Part 6: OSPF LSA Types - Purpose and Function o…
Our previous article explained the purpose of Link State Update (LSU) packets and examined the Link State Advertisement (LSA) information contained within…
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…
SASE & SD-WAN Networks
How To Secure Your SD-WAN. Comparing DIY, Managed SD-W…
With so much enterprise network traffic now destined for the cloud, backhauling traffic across an expensive MPLS connection to a data center to apply secu…
SASE & SD-WAN Networks
Configuring A SASE Unified Network: Data centers, Remo…
This article explores the need for Secure Access Service Edge (SASE) in today’s organizations. We show how one of the most advanced SASE platforms availab…
Palo Alto Networks
The Ultimate Guide to Palo Alto Networks Software NGFW…
Discover the ins and outs of using Palo Alto Networks’ Software NGFW (Flex) credits to seamlessly renew your cloud-based or virtualized software NGFW devi…
Cisco Firewalls
Cisco ASA Firepower Threat Defense (FTD): Download and…
One Appliance – One Image is what Cisco is targeting for its Next Generation Firewalls. With this vision, Cisco has created a unified software image named…







