Quick Lab - RIPv2 Auto Summary

December 27, 2019

RIPv2’s automatic network summarization feature is easy to misunderstand, which can be a recipe for disaster in a production environment or on the CCIE R&S lab exam. Let’s analyze the exact behavior behind this feature by experimenting with it in a quick lab!

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Deep Dive - IEEE 802.1D Spanning Tree Topology Change

December 14, 2019

While reviewing the IEEE 802.1D Spanning Tree Protocol Topology Change Notification mechanism, I felt some confusion as to the exact behavior that each bridge exhibits when a topology change occurs. This post documents my journey to alleviate this confusion in the lab!

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Quick Mystery - Spanning Tree Priority

November 29, 2019

One aspect of Spanning Tree Protocol I became curious about during my CCIE studies was the exact behavior behind how Spanning Tree bridge priorities are modified using the spanning-tree vlan {vlan-id} root {primary | secondary} configuration command. This post explores this behavior in the lab!

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Bringing The Gap - Frame Relay

December 6, 2017

When the ICND1, ICND2, and CCNA R&S composite exams were updated to their latest versions on August 20th, 2016, Frame Relay technology was removed from the exam topics. However, network engineers who obtained their CCNA R&S certification using these new exams and want to pursue their CCNP R&S certification will find that Frame Relay is still in the exam topics under the CCNP ROUTE exam, as well as lingering in the CCIE R&S exam as well! This can make learning an otherwise-legacy technology extremely difficult, especially as there are fewer and fewer real-world examples to draw from.

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Basics of IOS XR Software

November 29, 2017

This article highlights the basics of IOS XR software, with the end goal being the education of an individual who desires to understand and upgrade the software of an IOS XR device. Topics that are covered include software types and states, software package downloading, addition, installation, and commission, turbobooting an IOS XR device, and some common caveats an individual might encounter when upgrading or downgrading the software of an IOS XR device.

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Auto-MDIX Capabilities on Cisco 1800s, 2800s, and 3800s

November 26, 2017

A common question I have seen asked is what models of Cisco 1800s, 2800s, and 3800s support auto-MDIX, a feature that allows for Ethernet cables with almost any pinout to connect devices together. This question has become prevalent now that these devices are becoming more affordable on the used Cisco market, making them especially prominent in home or business lab environments. I have personally tested all of the below devices to verify the presence or absence of auto-MDIX.

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Cisco TCL Script Not Running Configure Replace

August 8, 2017

During the research phase of my networking homelab initial configuration automation article, I explored many different options on how to easily deploy a base configuration to devices that had been reset to factory defaults. One of the options I tested involved TCL scripts, where a script would reset the device to factory settings, then use the configure replace command to introduce a predefined configuration. This configuration would establish remote access, define IP addressing across management interfaces, create usernames and passwords, and implement any other convenient commands for the user. The configure replace command worked extraordinarily well: SSH could be used for remote access because cryptographic keys could be loaded into the base configuration, there was no need to reload any devices in order to revert to the base configuration, and a previous Telnet or SSH session would not be interrupted at all when the configure replace command is run.

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Automating Base Configuration in a Cisco Networking Homelab

August 8, 2017

Let’s face it: resetting Cisco devices in your homelab to factory defaults is painful. The process of plugging in a console cable, erasing the contents of the NVRAM, reloading the device, then initially configuring the device so that you can remotely access it is bearable for a single device, but most networking homelabs have six devices, sometimes more! Modern Cisco devices solve this issue with dedicated management interfaces that retain their configuration even after a write erase command, but these devices tend to be outside the budget of somebody studying for their CCNA or CCNP. One common solution is a router acting as a terminal server, which uses reverse telnet to remotely console into devices using the console or aux ports; however, the total cost of such a project easily can be hundreds of dollars and can be difficult for somebody new to Cisco devices to configure.

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A Homelab Update!

April 2, 2017

A lot has changed with my homelab since my first post, and unfortunately, my website has remained devoid of any updates. That is definitely going to change during 2017! To start off, let’s take a look at the latest lab topology, then I’ll explain what has changed since the previous update and my rationale behind certain decisions.

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Schick Technologies USBCam2 Intraoral Camera Appears In Device Manager As USB2820 Device

August 23, 2016

I’ve encountered an issue recently with a Schick Technologies USBCam2 intraoral camera appearing as a USB2820 device in Device Manager when plugged into a Dell Vostro 1520 laptop. I am not sure at this time if this is an issue between this particular laptop and the intraoral camera, or if this issue can occur with other laptop models as well. For me, this issue occurred regardless of which USB port the camera was plugged into. When the camera is acting under the USB2820 device, it does not display any video within dental practice management software or image capturing software (in this case, I was working with Eaglesoft.)

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Installing/Reinstalling Windows 7 on a Dell Latitude E5570

August 23, 2016

I encountered an issue with a Dell Latitude E5570 where Windows 7 reported that the laptop’s BCD was either missing or corrupted. Upon attempting to rebuild the BCD using Windows 7 installation media, I received an odd error reporting that “The requested system device cannot be found”, even when it successfully detected the Windows installation of the laptop’s hard drive. I also noticed that in DISKPART, my installation media was not showing up as a disk (only the hard drive of the laptop appeared). At first, I believed that my USB 3.0 flash drive might be causing some issues, so I attempted to swap to USB 2.0 installation media – this did not help either.

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Establishing A Baseline

January 25, 2016

Lao Tzu, a Chinese philosopher, once said that “the journey of a thousand miles starts with a single step.” Although the journey of my homelab started over a year ago, it has remained largely undocumented. Blog posts like these (in combination with an internal wiki that I have set up) strive towards resolving that issue, as well as allowing others a glimpse into the infrastructure I have created and learn something from it (or, as is more likely, tell me that what I’m trying to do is very, very wrong.)

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