Cacti is a popular open source networking tool that is web based, and it is used both for network monitoring and graphing. In my work environment we use Cacti extensively to mainly monitor bandwidth on interfaces of switches etc. It is a complex tool to learn but very powerful. With Cacti you can poll services, […]
[Continue reading]Learning to configure your Cisco devices from the Command Line Interface (CLI) is an essential step towards your Cisco networking career. This means that you need to learn how to configure the Cisco IOS operating system which runs on routers, switches and other network devices. Acquiring this hands-on experience with the Cisco IOS CLI will […]
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On this website I have written tens of articles about enterprise level firewalls (especially Cisco ASA) but many people are interested to learn about the best hardware firewalls for home or small business networks, so this is what I’ll focus in this article. Firewalls are designed to monitor incoming and outgoing traffic, helping to keep […]
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As network engineers and administrators, we mostly focus on managing and configuring hardware devices such as routers, switches, firewalls, load balancers etc. We rarely deal with software management tools which are equally important in a corporate network. Without knowing the health, performance, availability and quality of your network is like running with closed eyes. Network […]
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Usually, in the world of network security, when we talk about Firewalls we mean the devices that help protect your computer systems and networks from attacks and provide a “wall” in front of servers and IT resources. The above concept of a “Firewall” refers to the classic network hardware firewall such as the Cisco ASA, […]
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Every host or device that is connected to a TCP/IP network must have two addresses in order to send and receive traffic on the network. These are MAC and IP addresses. Knowing the details and functionality of these two address types is essential for anyone working in networking or in I.T in general. In this […]
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Imagine the following situation: You are a network engineer and your boss or a customer wants you to build a cheap and easy solution to host a publicly accessible server (such as Webserver, Email server, VPN server etc) using only a regular Cisco router. In most network designs, you will see that the usual and […]
[Continue reading]One of the most frequent problems encountered from users of DSL internet connectivity (especially PPPoE DSL service) is when they experience incomplete connections or unreliable data transfers when they communicate with internet servers. A prominent example is when a user accesses a web site and some times it works and some times it does not. […]
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A few decades ago, flat networks were the norm. I remember in my very first job as a network engineer, most of our clients’ networks consisted of a single broadcast domain (VLAN) and a huge single flat Layer 3 network (usually in the 10.0.0.0 range). As time passed by and networks started to become bigger […]
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FTP and HTTP are two of the oldest network protocols in existence. Although they made their appearance in the nineteen-eighties, they are still among the most popular network protocols used in Information Technology and Internet in general. HTTP is an acronym for Hypertext Transfer Protocol. FTP is an acronym short for File Transfer Protocol. Both […]
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If you are a networking professional that is operating and supporting Cisco devices and networks, then learning some important “show commands” is essential. There are a few different categories of commands on Cisco devices. There are commands that configure the device to perform a certain function and also there are commands that extract information from […]
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Routing and Switching form the foundation of computer networks and the Internet in general. A network engineer must know routing principles like the back of his/her hand!! In this practical tutorial we will discuss the Cisco “show ip route” command which allows a network engineer to examine the routing table of a router device in […]
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Cisco devices offer excellent features for traffic filtering. The classic Access Control List (ACL) is the core mechanism on Cisco network devices (routers, switches etc) which is mainly used for traffic filtering. In this article we will examine a different type of ACL, called the Vlan Access Control List (VACL) which works a little different […]
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