What this site is all about

The purpose of this site is to explore interesting, caveat and quirky scenarios that make Network Engineering interesting and fun. Blogs will be posted once every few months and will share a variety of scenarios with a focus on an Internet Service Provider perspective.

A secondary function of this site is to share knowledge. This includes study notes, general information, lab topologies, scripts and the like.

Site Layout

This site is laid out into the following sections:

  • Posts – My main page where I will blog about quirks that I come across. Posts will either discuss a general topics of interest or specific quirky scenarios. When discussing a scenario, each post will be divided into 3 parts:
    • The quirk – the scenario description
    • The search – or processes involved in working towards a solution
    • The work – the technical details (including CLI if applicable) used to implement the solution.
  • Notes & Cheat Sheets – My documentation, including study notes, how-to documents and cert guides.
  • Labs – Preconfigured GNS3 and EVE-NG topologies for download.
  • IOS vs XR – A like-for-like comparison of Cisco IOS and IOS-XR CLI configuration for a range of topologies and scenarios.
  • Scripts – Contains scripts that are kept on GitHub. These scripts will usually be python based and will aid in areas like network automation.
  • Quick Reference Tables – Tables detailing the timers, election processes and default values of various protocols.
  • Acronym Index – Just what it says, a list of networks acronyms sorted by topic. To be updated over time.

About me


My name is Steve Crutchley and I’m a Network Engineer living and working in central London. Originally from New Zealand, I currently work on the core Networks team for a Managed Service Provider.

As I have progressed through my career I’ve come across a lot of unique scenarios that have helped me grow and learn. I believe it would be beneficial, both for others and myself, to share some of these scenarios. In addition to this, I have made a plethora of study notes and on the job documentation throughout my time as an engineer. My colleagues have frequently commented that it would be handy to access to these notes and that they could come in useful for others.

My experience includes an array of Networking technologies. From Routing and Switching, Voice, ASA/Juniper Firewalls, Python and Java programming and more. From a CLI perspective, I’ve largely dealt with Cisco, but have experience in ScreenOS and Junos as well.

I hold the following certifications, the most recent of which is my CCNP SP:

  • Bachelor of Science – Double Major in Computer Science & Philosophy
  • Bachelor of Arts – Majoring in Logic and Computation
  • CCNA Security
  • CCNP Routing & Switching
  • CCNP Service Provider
  • ITIL Foundations version 3

I’m also a Cisco Champion.

This is the first blog site I have ever made, so I imagine it will change and grow over time. I will do my best to make the information I share interesting and informative. I hope you enjoy the read.

On a more personal note, I play guitar, am an avid runner and a die hard fan of Indiana Jones.

Where you come in

In the hopes of finding out what works and what doesn’t, I would be very interested in getting feedback on which blogs and features are useful and which are not. If there is a topic, lab or script that you’d like to see, let me know. Perhaps most crucially, if you believe I have made a technical error please feel free to hit me up about it. I’ve done my best to make the information here as accurate as possible but mistakes happen.

The best way to get in touch is through the contact page.


I should note that whilst some of the ideas and blogs on this site are drawn from my own experience, they do not necessarily reflect the specific scenarios, configurations or design solutions of any company I have worked with or their customers.

It should also be pointed out that notes and documents will reference public IP addresses. This is not a reference in any way to the holder of that public IP and any such implication is entirely unintentional.

With respect to the certification guides found in the Docs section, some of the guides are for out of date versions of the certifications. Whilst the certifications I hold are current and valid, the courses’ content may have changed since the notes were first produced. Having said that, they should still cover a significant amount of the current course curriculum.

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