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Articles:
The OSI Model: Layer 5 - Session Layer
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The OSI Model: Layer 4 - Transport Layer
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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 - Part 6: Redirect Messages
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…
CAT5, CAT5e, CAT6 UTP X-Over / Cross-over Cable
The cross-over (or crossover) CAT5 UTP cable has to be one of the most used cables after the classic straight-thru cable. The cross-over cable allows…
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…
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…
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…
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…
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…
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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…
InterVLAN Routing - Routing between VLAN Networks
This article deals with the popular topic of InterVLAN routing, which is used to allow routing & communication between VLAN networks. Our article anal…
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…
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…
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…
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 Information Protocol - RIP
Routing Information Protocol (RIP) is a distance-vector routing protocol that is commonly used in small to medium-sized networks. It is one of the o…
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…
How to Fix Palo Alto Firewall “Error: Image File Authe…
Keeping your Palo Alto Firewall up to date with the latest PAN-OS software updates is an important step to ensure your organization is protected against t…
Converting Cisco Firepower from Platform mode to Appli…
This article explains how to configure a Cisco Firepower 2100 series device to operate in Appliance mode. We’ll show you how to switch from Platform mode…
Understanding Secure Access Service Edge (SASE) and ho…
Software Defined Wide Area Networking (SD-WAN) is changing the way that businesses connect to the cloud. With SD-WAN, organizations can move away from clo…
Resolving Cisco Router/Switch Tftp Problems: Source IP…
When working with Cisco equipment that has multiple ip interfaces, a common problem engineers are faced with is trying to successfully tftp to or from the…