Articles
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Articles:
The OSI Model: Layer 5 - Session Layer
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Articles:
The OSI Model: Layer 4 - Transport Layer
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Articles:
The OSI Model: Layer 3 - Network Layer
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The OSI Model: Layer 2 - Datalink Layer
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The OSI Model: Layer 1 - Physical Layer
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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…
Network Cabling
USB Direct Cable Connection, USB Versions, Specif…
Today, Serial and Parallel Direct Cable Connections are considered obsolete methods of transferring data between computers. The fact is that even USB…
Ethernet Protocol, CSMA/CD, Collisions
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CSMA/CD stands for Carrier Sense Multiple Access with Collision Detection. It refers to the means of media access, or deciding "who gets to talk" in…
Domain Name System (DNS)
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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…
Featured Subcategories:
Netflow Articles:
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…
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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…
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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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Cisco Password Crack
Decrypt Cisco Type-7 Passwords on the fly!
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
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
VLAN InterSwitch Link (ISL) Protocol Analysis
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…
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…
Routing
Enhanced Interior Gateway Routing Protocol - EIGRP
Enhanced Interior Gateway Routing Protocol (EIGRP), similar to IGRP, is a Cisco proprietary routing protocol that is used to exchange routing information…
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
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…
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
Upgrading - Uploading AnyConnect Secure Mobility Clien…
This article will show how to download and upload the newer AnyConnect 4.x VPN clients to your Cisco ASA Firewall appliance (5500 & 5500-X Series) and…
Windows Servers
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This article serves as an Active Directory tutorial covering installation and setup of a Windows 2012 Domain Controller using Windows Server Manager (GUI)…
Cisco Routers
Cisco Router Password Recovery
Password recovery is a fairly frequently used procedure for administrators and engineers. Even though we usually stack our passwords in some word, excel o…







