I’m generally a big fan of encrypted DNS for the security it provides with negligible performance impact. But I recently found out the hard way that DNS over TLS/HTTPS can deadlock with Network Time Protocol (NTP) on embedded devices without a battery-backed real-time clock. Many low-cost routers lack a battery…

Let’s say you want to run a BIG query with gigabytes of results. How do you do it? Plain Query With a plain query, you load the entire result set into client RAM. If it’s even possible, you are either at risk of the Out-Of-Memory killer killing your process, or you are…

No matter what backup program you run, using a point-in-time filesystem snapshot is required to achieve correct backups of a running system. A handful of backup programs handle these automatically, but most require you to do it yourself. If you run a backup without snapshot support while web browsing, there’s…

Traditional DNS is over UDP, a connectionless protocol with no setup. DNS-over-TLS (DoT) wraps DNS requests in a TLS connection, which itself goes over a TCP connection. Transport Layer Security (TLS) is the successor to Secure Sockets Layer (SSL), and is what secures most of today’s web browsing traffic. In…

Let’s take a look at the costs and benefits of enabling DNSSEC validation on the forwarding DNS resolver in your home or business. In our scenario there is a small to medium network that has a forwarding DNS resolver at the edge, such as on the router. The forwarding resolver…

Jimmy Wales, the founder of Wikipedia, is emailing me? “Signing off”? Is he leaving Wikipedia? Is he dying?! No, just asking for more money. It’s funny, I think he’s said this exact thing before.

I type my password many times a day to unlock my laptop, but I can’t tell you what it is. I don’t really know it. Let me explain… Many years ago the allure of a more efficient keyboard layout with faster typing speed and less wrist pain prompted me to…

DNS records originate from controlling nameservers and are cached at multiple levels: your ISP or a public resolver like Google’s or Cloudflare’s, possibly your router, your operating system, and even your browser. …

When you resume a tmux session on a remote server, tmux aims to restore the environment exactly as it was when you left. That’s great, except when you need things to change. The SSH_AUTH_SOCK and DISPLAY environment variables are set by SSH when the connection is established, and are inherited…