Getting Real with GNS3 – connecting to physical networks

This short guide shows how you can connect emulated routers with physical routers using GNS3 and the Ethernet NIO. This is a cheap method for expanding your home networking lab, and it is amazingly simple. Whilst I’m using Windows, the same method will work with Linux too.

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Configuring a Cisco 2509-RJ terminal server

I recently purchased myself a cisco 2509-RJ, which is similar to the 2509 / 2511, however rather than an octopus cable to connect to other devices, RJ45-RJ45 rollover cables are used. This article shows a full configuration example and details on the cables required. The configuration allows for reverse telneting into other devices.

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IP Subnetting made easy – A subnetting tutorial

I’ve been asked to help people understand subetting and CIDR a few times.  In this post I give a short tutorial. Subnetting is explained in many places, with a large variety of methods. The key to working out valid subnets however is simply a matter of understanding the binary maths behind it.

This guide teaches you a simple method, suitable for the Cisco CCNA or ICND1 exam.

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