Converting Hexadecimal to Decimal and Binary

The purpose of this post is to reference the CCNA Data Center (640-911) exam. This exam starts the conversation of IPv6 and since IPv6 is hexadecimal this post starts the talk about how we look at a hexadecimal values and learn how to convert them to binary and decimal. If you know subnetting skills then this won’t be that difficult. If you are new then check out The Wonders of Binary post as well as Part 1 and Part 2 of subnetting. Let’s get started! Continue reading

Configuring Rancid

In my last post I talked about installing Rancid on Centos 7 so be sure to check that out. In this post we now want to actually use Rancid so I’ll walk through on how to setup Rancid to login into network equipment and get configurations. To recap: Rancid is a great tool to help monitor a device configuration for any changes. It also keeps track of them by using CVS (Concurrent Version System) for backups, so you can go back and compare versions or revert to a previous configuration. Rancid supports multiple hardware from Cisco, HP, Dell, Juniper and more. This is all open-source so you can create custom scripts or add commands to really make this a personal repository that fits your company. Continue reading

Setting up GNS3 1.1 on Ubuntu

gns3_logoIt’s only been a week since GNS3 1.0 was released and it’s already been updated to 1.1 so in this post I have Ubuntu 14.04 LTS with the latest updates and its time to set up GNS3. GNS3 is an open source tool that helps network professionals run a virtual network right on their computer, GNS3 is not a simulation program but rather an emulation program. So if you wanted to test a configuration change but did not want to run it on production you can run it in GNS3 instead.  This gives network professionals testing without touching any physical hardware or purchasing that expensive test lab for certification studies. Let’s get started. Continue reading

Setting up Enhanced vPC on Nexus 5600

So I’ve played around with two Cisco Nexus 5672UP switches which will be in production soon but before that I wanted to see what it took to get enhanced vPC online. Along the way I was into some new territory as I never stood up vPC before, so in this post I have posted some things to keep in mind and running-config examples, all of which I hope is helpful for a reference. Continue reading

Some QoS Guidelines

When I started taking classes from the Cisco CCNA Discover books years ago, I remember for the first part of the book it talked about QoS and the theory behind it. To me QoS was a very interesting but after a chapter or two we never mentioned it again or really knew how to configure it. It seemed like it disappeared but it always something being tested on so we know it was there, somewhere… QoS can be a little boring and it does get a reputation of being difficult to understand, like where and how do I implement QoS? Most of the time QoS is not configured which causes applications to suffer in the end have an impact of end user performance. Throwing bandwidth to fix the problem is usually a costly risk, and remember you still may have the same performance problems. What also makes it interesting is you may have an environment that runs fine without QoS, so why do you need it? Well there’s no easy button to fix or find these unanswered questions about QoS. In this post I’m referencing guidelines of where to start looking which will hopefully help answer some of those unanswered questions. 🙂 Continue reading