Articles That Might Interest:

Cisco Data Center (Nexus/UCS)

Nexus 7000/7700 Software Upgrade via ISSU. Comple…

This article shows how to perform an ISSU (In-Service Software Upgrade) on a Nexus Data Center switch (7000 and 7700 models) and avoid service and network disruption. We explain the importance of kee…

Network Cabling

Serial Direct Cable Connection, DB9, DB25, COM Po…

This article covers the popular serial ports on workstations, servers and laptop computers. We cover serial data transfer, port pinouts, port speeds, serial interface types (DB9 & DB25), null mod…

Cisco Firewalls

Cisco ASA 5500 Series Firewall Modules & Cards –…

Cisco’s Adaptive Security Appliance (ASA) Firewalls are one of the most popular and proven security solutions in the industry. Since the introduction of the PIX and ASA Firewall into the market, Cisc…

TCP - UDP Protocol Analysis

Transmission Control Protocol - Part 4: In-Depth…

This article is an introduction to the 7-page TCP Header analysis section that follows. We briefly view each section of the TCP Header and then move on to its analysis using detailed colourful diagra…

VPN Services & Guides

DNS Leak Testing & Protection – How to Avoid Expo…

Despite innovations in security and technology, it’s difficult to remain anonymous online. Identifying information is seemingly everywhere – from malicious JavaScript tracking to the location service…

Subnetting

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 different methods that can be used to enable subnet comm…

Cisco Routers

Configuring PPTP (VPDN) Server On A Cisco Router

The Point to Point Tunneling Protocol (PPTP) is a network protocol used to create VPN tunnels between public networks. These VPN tunnels are encrypted from one end to the other and allow the secure t…

Network Cabling

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 us to connect two computers without needing a hub…

Cisco Routers

Cisco Router Basic ISDN Configuration

Configuration of ISDN interfaces on Cisco routers are usually considered a straight-forward process, however there are some details which can cause your ISDN dialer interface to fail. This article w…

Routing

OSPF - Part 6: OSPF LSA Types - Purpose and Funct…

Our previous article explained the purpose of Link State Update (LSU) packets and examined the Link State Advertisement (LSA) information contained within LSU packets. We also saw the most common LSA…

Network Cabling

Early Communication Technology - Morse Code and E…

We tend to think of digital communication as a new idea but in 1844 a man called Samuel Morse sent a message 37 miles from Washington D.C. to Baltimore, using his new invention ‘The Telegraph’. This…

Network Fundamentals

Introduction To Networking

A network is simply a group of two or more Personal Computers linked together. Many types of networks exist, but the most common types of networks are Local-Area Networks (LANs), and Wide-Area Networ…