networking

tailscale up --tun=userspace-networking gets you a green dot in the admin console and almost nothing else. The node appears in your tailnet, tailscale status looks healthy, and then you try to SSH into that container from your laptop and the connection hangs until TCP gives up. Two lines in the LXC config file fix it, and the container stays unprivileged. That's the whole post, really. But those …

A device is normally configured with a single IP address for its DNS resolver. That address reaches the resolver over plain, unencrypted DNS, which is all a bare IP address can describe. Encrypted DNS requires more: a hostname to check the certificate against, a port, and a protocol. None of that fits in the settings box, and none of it can be worked out from the address already sitting there. DD…

The history of networking is full of tools that repurposed solutions to very different kinds of problems first. Wi-Fi’s origins trace back , in part, to a team of Australian radio astronomers trying to detect signals from evaporating black holes. But the data-processing tools they’d developed also proved capable at extracting clean messages from any chaotic, echoing signal environment . Echoes ar…

Disclosure before we start: I build the native iPerf3 apps for iPhone, iPad, Mac, and Android mentioned near the end. Everything in this post also works with the free iperf3 CLI on two computers. The phone enters the picture when one endpoint has to move around the building. Speedtest answers one question: how fast is the path from your device to the ISP's nearest test server. Inside a home or of…

How to Turn an Unreliable Protocol into One You Can Trust When most developers think about networking, they immediately think of TCP . After all, TCP powers web browsing, APIs, databases, email, and countless distributed systems. It guarantees that data arrives in order, without duplication, and without corruption. But there's another protocol that quietly powers some of the fastest systems in th…

Prologue At ArcBox Labs, our office has a 5 Gbps PPPoE connection behind a UniFi gateway, and we could never get anywhere close to that speed, and our UDM Pro Max is beginning to struggle and even affecting operation stability: This matches the behavior observed by many other UniFi users: - https://community.ui.com/questions/a6f24f8c-6b83-4617-ad33-b5af0b32d8dc?replyId=2808b654-e4be-4ac2-b199-09c…

If you're learning DevOps, networking is not optional. Every SSH connection, web request, Docker container, Kubernetes service, and cloud resource relies on networking behind the scenes. When applications fail to communicate, deployments break, or services become unreachable, networking is often the first place engineers investigate. In this article, I'll cover: ✅ What IP addresses are ✅ Public v…

Getting 25 Gbps Thunderbolt Ethernet on my Mac Studio I've been using the built-in 10 Gigabit Ethernet on my Mac Studio for a few years. It works fine: I can edit 4K video straight off my NAS over the network, and run backups at around 1 GB/sec. But... I want more. I upgraded my rack and my NAS to 25 GbE a couple years ago, and wanted to upgrade my main workstation, too. I looked up 25G networkin…

On Ubuntu, it is common to use Netplan to attach an Ethernet interface to a Linux bridge. On Rocky Linux 9, however, NetworkManager typically manages networking. Instead of Netplan, Rocky Linux uses nmcli to create a bridge and attach the physical network interface to it. This article explains how to achieve the equivalent of an Ubuntu Netplan bridge configuration on Rocky Linux 9. Network Topolo…

Today I am taking a look at the weird world of multicast, where packets get delivered more than once, and we route using a backwards routing table. But, once you understand how it works, a whole world of content distribution possibilities open up to you! Inspired by an old video by @TallPaulTech, I’m using live TV distribution as an example of how multicast works, and how it can potentially be a …

1. Analogy Imagine you're sending your friend a 500-page book. You have two delivery companies. The first guarantees every page arrives in order. If page 187 gets lost, they'll resend only page 187. The second company is incredibly fast. They throw pages onto trucks immediately. If page 187 disappears... They simply keep driving. Which company would you choose? The answer depends on what you're s…