Bits, Bytes, & Radio Waves

A quiet journey through discovery and understanding.

  • Using Local SPAN to Troubleshoot and Resolve Problems

    A Switched Port Analyzer, or SPAN, is a way that you can monitor traffic. Back when networks used hubs, all traffic was visible because a hub just repeated the traffic out every port except the one it came in on. When switches were introduced, SPAN functionality was introduced to accommodate. It is common to set…

  • ICMP Echo-Based IP SLA

    Internet Control Message Protocol (ICMP) is a commonly used utility to test Layer 3 connectivity between devices. A Service Level Agreement (SLA) is a target that must be met; there is no set criteria for an SLA. ICMP echo-based IP SLA is a way to monitor end-to-end response time between Cisco devices using IPv4 or…

  • Connecting to IPv6 Websites by IP

    Internet Protocol version 6 (IPv6) request for comments (RFC) 1883 (https://tools.ietf.org/html/rfc1883) came out in December 1995. That’s 22 years ago! So how do you connect to an IPv6 address without using a Domain Name Server (DNS)? It’s only slightly different than Internet Protocol version 4 (IPv4). You do need to make sure you have an…

Notes from practice

I use this site to document systems, configurations, and lessons learned as I work through real problems—both professionally and through personal experimentation. The goal is clarity: understand how something works, explain why it behaves the way it does, and make it reliable and repeatable.

These notes are written primarily for myself, but shared openly in case they help someone else avoid a dead end or reduce frustration. If you’d like to learn more, visit the About page.

If you have questions or comments, you’re always welcome to contact me.

Aaron Rombaut

Technologist & Writer