I was reminded by @dritans tweet that there a lot of great NANOG presentations which tend to get buried amongst the archives.
The particular one he linked to is A Practical Guide to (Correctly) Troubleshooting with Traceroute [222KB PDF] by Richard A Steenbergen. This is a terrific primer for those who have never dug deep into traceroute tools, how they work and what they can show you. It’s quite easy to misinterpret what a traceroute tool’s results actually mean and RAS steps you through the various anomalies and pitfalls.
The complexity covered here is why asking job candidates about traceroute tools is a great way to expose understanding of, or ignorance of, the basics of packet switched networks, IP and TCP/UDP/ICMP. You can also learn a lot about their approach to troubleshooting and analysis of data, whether they can turn it into useful information and communicate that.
The other presentation I was reminded of is Managing IP Networks with Free Software [400KB PDF] by Joe Abley and Stephen Stuart. It’s getting on a bit, NANOG 26 was in late 2002, but it’s still an interesting showcase of how you can get [nearly] instant results with some simple tools and a little scripting.
I’d like to say that things have changed in the decade since and we now have a one size fits all tool that achieves a lot of the same goals but due to every organisation’s different needs everyone keeps reinventing subtly different wheels. Hence I’ve been down the same path, installing RANCID and then building things around it. I just wish I’d known about textfsm, a Python module for parsing semi-structured text (e.g. ‘show run’ output) into tabular data.
Do you have any favourite NANOG presentations?