Stop using PowerPoint as a working document

I’m spending more time working with people with management titles, and I find a few things disturbing. I have attended working sessions where the collaborative document was a PowerPoint slide deck. That was super confusing to me because a slide deck is something I have used when I had to attend a conference to give a talk about a specific topic. A PowerPoint slide deck as a work deliverable blew my mind.

Mirroring a container registry

I was working on an article How to run an air gap installation of OpenNMS Horizon on Rocky Linux. I ran into a similar use case and it was not about RPMs or DEB packages, it was all about container images and registries. My question was, how can I get “all” container images into a private registry from DockerHub? Getting your hands dirty with a private registry is something I’ve described in Running a private container registry for testing. Here is a short how-to on how I did it for my future self or anyone else with a similar question.

Make your network traffic visible using flows

Getting metrics about the utilization of network interfaces isn’t very complicated these days. Most of the time your network gear is instrumented with an SNMP agent which you can use to measure it or if you get modern, they have telemetry streaming, and they send you measurements with protocols like gNMI. I’m not explaining fancy new tech here, everything mentioned here is old, but your devices might have these capabilities but aren’t exploited :)

Net-SNMP version 3 and OpenNMS

To monitor your systems you rely heavily on SNMP, it gives out of the box a lot of possibilities getting important performance and status information.

The main topic security is often not considered. SNMP version 1 and 2c transmit everything in plain text over the wire. There is also no user, password authentication method, just a shared community string which gives access to the information. To address these problems SNMP v3 was introduced.

IPv6 prefix delegation with FRITZ!OS 7.50 and Ubiquiti ER-4

I started working remotely in 2010 for OpenNMS as an open-source network monitoring advocate. I have a little home lab with some real hardware that allows me to play on various things without giving me a big surprise bill from a cloud provider at the end of the month. I have a FRITZ!Box 7530 connected to my ISP 1&1. I get native IPv6 and IPv4 connectivity over an IPv4-in-IPv6-Tunnel. As my main router, I have a Ubiquiti ER-4. It gives me enhanced firewall capabilities and flexibility, especially with routing protocols like OSPF and BGP. I have two networks, one for my work-related stuff and another with all the fun crap you have for fun at home.

Running a private container registry for testing

When I signed up for my DockerHub account in 2013, I never thought sooner than later everything ends up in a container image as it is today. DockerHub was the first public free as in free beer registry to distribute your container images. Containers are now everywhere, and DockerHub, a corporate entity running and funding DockerHub, introduced usage limits for the free tier and started commercializing its registry service. I need to play with software in a micro-service architecture on a platform like Kubernetes, and these limits can be daunting.