Articles
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Articles:
ISDN Layers, Protocols & Components
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Articles:
Introduction To The ISDN Protocol
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Articles:
Introduction To Protocols
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Articles:
File Transfer Protocol - FTP
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Articles:
Trivial File Transport Protocol - TFTP
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Articles:
IPSec - Internet Protocol Security
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TCP - UDP Protocol Analysis
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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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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
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
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If you've read our previous article The VLAN Concept - Introduction to VLANs then you should feel comfortable with terms such as 'VLAN', 'Stati…
VLAN Networks
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The invention of VLANs was very much welcomed by all engineers and administrators, allowing them to extend, redesign and segment their existing network wi…
Routing
OSPF - Part 2: How OSPF Protocol Works & Basic Concept…
This article covers basic OSPF concepts and operation. We explain how OSPF works, how OSPF tables are built on an OSPF-enabled router and their purpose (N…
Routing
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 interf…
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Our previous article explained the purpose of Link State Update (LSU) packets and examined the Link State Advertisement (LSA) information contained within…
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GRE Tunnels are very common amongst VPN implementations thanks to their simplicity and ease of configuration. With broadcasting and multicasting support…
Cisco Routers
How To Configure DHCP Server On A Cisco Router
DHCP (Dynamic Host Configuration Protocol) is the protocol used by network devices (such as PCs, network printers, etc) to automatically obtain correct ne…
Virtualization & VM Backup
How to Fix VMware ESXi Virtual Machine 'Invalid Status'
In this article, we'll show you how to deal with VMs which are reported to have an Invalid Status as shown in the screenshot below. This is a common…
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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…







