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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Using VERP with swiftmailer, symfony and exim

VERP ( provides a method for handling bounced emails. This is especially useful when it comes to figuring out which emails failed to get delivered from your application/mail outs. This post covers how I got this working in symfony using swiftmailer to send the mail, and exim to deliver bounces back into symfony. The concepts shown can be applied to just about any combination of software though.

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Date/Time Range Selector Widget for Symfony

I needed to create a date/time widget for use in an sfForm in a symfony project I was working on, and unfortunately there’s not currently a widget that I could find to allow this. In this post I show how I solved this problem, creating a widget for selecting a date range, using the jquery date selector from sfFormExtraPlugin.

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