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Suggested Articles:
Ethernet Protocol, CSMA/CD, Collisions
The IEEE 802.3 SNAP Frame Format
While the original 802.3 specification worked well, the IEEE realized that some upper layer protocols required an Ethertype to work properly. For exa…
Network Fundamentals
Media Access Control - MAC Addresses
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…
Ethernet Protocol, CSMA/CD, Collisions
Integrating Fast Ethernet into 10MB Ethernet Netw…
Now that Fast Ethernet is here, the question becomes, "How do I start using it ?" Integrating Fast Ethernet into existing networks need not be done a…
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:
Bandwidth Detective: Uncover Hidden Traffic and E…
In this article, we explore the core principles of bandwidth management and examine how modern network monitoring technologies can assist in maintain…
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 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: 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
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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
VLANs - IEEE 802.1q Trunk Link Protocol Analysis
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
VLAN Security - Making the Most of VLANs
It's easy to see why virtual LANs have become extremely popular on networks of all sizes. In practical terms, multiple VLANs are pretty much the same as h…
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…
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 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
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
Interior Gateway Protocol - IGRP
IGRP (Interior Gateway Routing Protocol) is a Cisco proprietary distance-vector routing protocol used in enterprise networks to exchange routing informati…
Cisco Routers
Configuring Cisco SSL VPN AnyConnect (WebVPN) on Cisco…
Our Web SSL VPN article written back in 2011 introduced this new wave of VPN services. This article extends the topic by covering the installation a…
Palo Alto Networks
Introduction to Palo Alto Next-Generation Network Fire…
During the past decade, we’ve seen the global IT security market flooded with new network security and firewall security appliances. New vendors emerging…
Cisco Routers
How to Restrict Cisco IOS Router VPN Client to Layer-4…
In our article Cisco VPN Client Configuration - Setup for IOS Router we explained how to setup up a Cisco IOS router to support Cisco IPSec VPN clie…
Cisco Firewalls
Understand & Configure NAT Reflection, NAT Loopback, H…
This article examines the concept of NAT Reflection, also known as NAT Loopback or Hairpinning, and shows how to configure a Cisco ASA Firewall running AS…







