Network Fundamentals: Top Picks
The Importance of a Network Analyzer – Packet S...
Network Analyzers, also known as Packet Sniffers, are amongst the most popular network tools found inside any Network Engineer’s toolkit. A Network...
Need for Speed – The Data Tsunami & Advancement...
A long-long time ago (not long ago in earth time) 100 Mbps was THE technology. 100 Mbps uplinks bundled with ether-channel was the ultimate uplink ...
Measuring Network Performance: Test Network Thr...
Measuring network performance has always been a difficult and unclear task, mainly because most engineers and administrators are unsure which appro...
Firewall Topologies
In this section we are going to talk about the different ways a firewall can be set up. Depending on your needs, you can have a very simple firewal...
Featured Subcategories:
Netflow Articles:
Complete Guide to Netflow: How Netflow & its Co...
This article will cover the basics of Netflow, including its use cases, Netflow supported devices, Netflow history, and variants. We’ll also dive i...
NetFlow Analyzer: Free Download, Step-by-Step I...
In our previous article we explained how a Netflow Analyzer can help you gain visibility into your user traffic, application traffic and data flows...
Netflow vs SNMP. Two Different Approaches to Ne...
SNMP (Simple Network Management Protocol) and Netflow are both popular protocols with admins, prized for their ability to give visibility over the ...
Netflow: Monitor Bandwidth & Network Utilizatio...
Monitoring network traffic & bandwidth usage via Netflow is mandatory for any type and size network. Gaining visibility into user traffic, appl...
Network Protocols:
UDP Protocol - Header
This article covers the UDP protocol. We examine the structure of the UDP header, the protocols that use UDP as a transport plus a lot more.
Some ...
TCP Header Anaylsis - Section 2: TCP Sequence &...
This page will closely examine the Sequence and Acknowledgement numbers. The very purpose of their existence is related directly to the fact that t...
IP Subnetting - Part 1: The Basic Concepts
When we subnet a network, we basically split it into smaller networks. For example, when a set of IP Addresses is given to a company, e.g 254 they ...
IP Subnetting - Part 4: Routing Between Subnets
Routing and Communication between subnets is the main topic here. This article analyses communications between subnets. We provide examples on diff...
Supernetting In-Depth Analysis - Learn to Ident...
Our previous article served as an introduction to Supernetting, also known as Route Summarization. We covered the concept of Supernetting, how it w...
TCP Header Anaylsis - Section 3: TCP Header Len...
The third field under close examination is the TCP Header length. There really isn't that much to say about the Header length other than to explain...
IP Subnetting - Part 5: Subnetting Guidelines
There is always that day when you are called upon to provide a solution to a network problem. The number of problems that can occur in a network ar...
IP Subnetting - Part 3: Subnet Mask Bits & Anal...
So we have covered to some depth the subnetting topic, but there is still much to learn ! We are going to explain here the available subnet masks a...
STP/ICMP Protocols:
ICMP Protocol - Part 7: Time Exceeded Message A...
The ICMP - Time Exceeded message is one which is usually created by gateways or routers. In order to fully understand this ICMP message, you must b...
ICMP Protocol - Part 4: Destination Unreachable...
The 'ICMP Destination unreachable' message is quite interesting, because it doesn't actually contain one message, but infact six! This means that t...
Spanning Tree Protocol – Part 2: Rapid STP Port...
Spanning Tree Protocol, Rapid STP port costs and port states are an essential part of the STP algorithm that affect how STP decides to forward or b...
ICMP Protocol - Part 2: Echo / Echo Reply (Ping...
As mentioned in the previous page, an Echo is simply what we networking engineers call a 'ping'. The Echo Reply is, as most would guess, the ...
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VTP Introduction & Modes
The invention of VLANs was very much welcomed by all engineers and administrators, allowing them to extend, redesign and segment their existing network ...
Dynamic VLANs
Dynamic VLANs were introduced to grant the flexibility and complexity(!) that Static VLANs did not provide. Dynamic VLANs are quite rare because of thei...
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...
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 an...
OSPF - Part 4: OSPF Neighbor States – OSPF Neighbor ...
This is the third article of our OSPF series which analyzes the different OSPF States routers go through during the OSPF discovery and neighbor forming ...
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 inte...
OSPF - Part 1: Introduction, OSPF Packet Structure, ...
Open Shortest Path First (OSPF) is a popular routing protocol developed for Internet Protocol (IP) networks by the Interior Gateway Protocol (IGP) worki...
Hybrid Routing Protocols - Advantages and Disadvanta...
Hybrid routing protocols are a combination of distance-vector and link-state routing protocols, and are used to provide a more efficient and scala...