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How Passive Radar Works
Passive radar is radar that doesn't need a transmitter; it uses existing broadcasts of opportunity.
Topics /
Networking & Internet
The most popular blog posts about networking & internet on Hacker News. 216 posts.
122
Transfer files over an Ethernet patch cable
It's possible to just connect two computers together with Ethernet and do a bit of IP configuration:
123
Modern email can be built from borrowed parts
Let's design the successor to email on top of HTTP, fixing the design flaws SMTP has been dragging along for 40 years. Piece by piece. The goal is…
124
10Gb/s Ethernet: switching to a Broadcom SFP+ module
As predicted by several people, one of my Marvell-based SFP+ modules had overheating problems. I've switched it over to a Broadcom-based one, and it looks better, though I can't be certain.
125
IP Addresses Through 2025
It's time for another annual roundup from the world of IP addresses. Let’s see what has changed in the past 12 months in addressing the Internet and look at how IP address allocation information can inform us of the changing nature of the network itself.
126
Upcoming changes to Let's Encrypt and how they affect XMPP server operators
On 11th February, Let’s Encrypt will be rolling out a change to the certificates they issue to servers by default. Although there is generally nothing that Prosody operators need to do, servers using the new certificates may experience problems connecting to some other XMPP servers on the network.
127
World-first gigabit laser link between aircraft and geostationary satellite
Faster, more secure connections from space could one day make broadband on planes, ships and even remote roads as easy as turning on a light. The European Space Agency (ESA), Airbus Defence and Space, the Netherlands Organisation for Applied Scientific Research (TNO) and German payload manufacturer TESAT (as…
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129
SSH has no Host header
A dive into how we share IPs between VMs while making SSH work.
130
7zip.com Is Serving Malware
A convincing lookalike of the popular 7-Zip archiver site has been silently turning victims’ machines into residential proxy nodes.
131
A Terminal Protocol for Program Status (OSC 7501)
I wrote a specification for a new terminal escape sequence: OSC 7501, the Program Status Protocol . It lets any program tell the terminal what it's doing: idle, working, waiting on the user, finished, or failed, and why.
132
How We Made IPFS Content Publishing 10x Faster
How a statistical approach cut IPFS content publishing times by over one order of magnitude.
133
IP and DNS Leaks in WebKit Affecting Proxy Browsers and iCloud Private Relay
WebKit-based browsers on iOS and macOS can be configured to route all web traffic through proxy servers, which is how Tor browsers on iOS and our own Psylo work. We found three WebKit features — DNS prefetching, WebAuthn Related Origin Requests, and WebTransport — that bypass the configured proxy and send traffic…
134
I was right about ATProto key management
Note: this post has been revised to be split into two sections: a description of what happened, and my analysis. I hope to make it clear that, while I do not like ATProto in general, I am trying to make good-faith critcisms of specific design decisions and outcomes, and in fact, this post getting updoots on HackerNews…
135
Blackholing My Email
How Counter-Strike map credits led to my email address being harvested by worms, and why I had to ask my ISP to blackhole it.
136
Building on ATProto
If you prefer to receive all of my writing in your inbox, you can subscribe here. I strive to publish weekly, on Tuesday mornings.
137
ATProto spaces: A new extension to ATProto that enables non-public data
Atproto Spaces, formerly known as “the permissioned data protocol,” is a new extension to atproto that enables non-public data. The alpha is now officially open. Here’s how to develop with it and what to expect as we work towards the full release.
138
Boy I was wrong about the Fediverse
I have never been an "online community first" person. The internet is how I stay in touch with people I met in real life. I'm not a "tweet comments at celebrities" guy. I was never funny enough to be the funniest person on Twitter. So when Twitter was accidentally
139
Understanding Traceroute
I never understood how traceroute discovers each hop. Turns out it's a clever TTL trick, and about 80 lines of Rust.
140
Submarine cable resilience
The estimated 1.5M kilometres of subsea communications cables underpins our global telecommunication services. This critical infrastructure faces serious challenges in the coming years.
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How to get a free .arpa domain
Learn how to get a free .arpa domain by abusing IPv6 reverse DNS delegations on Hurricane Electric, configuring deSEC, and hosting a live website.
143
DNS Explained – How Domain Names Get Resolved
Learn how DNS works: hierarchy, records, TTL caching, and the full resolution process with diagrams.
144
FreeBSD Home NAS, part 3: WireGuard VPN, routing, and Linux peers
Setting up WireGuard VPN on FreeBSD 14.3: PF firewall, routing between networks, and peer-to-peer VPN between FreeBSD and Arch Linux
145
A macOS bug that causes TCP networking to stop working after 49.7 days
At Photon, we are developing the world’s most complete iMessage API (with RCS and SMS fallback) for agents: infrastructure that lets Agents reliably communicate through one of the most native messaging interfaces people already use. While building it, we run Mac-backed systems continuously and care a lot about making…
146
State of multi-player Wayland
I've been fascinated by the idea of attaching multiple mice to one computer, and then having multiple mouse cursors inside of one desktop environment!
147
Reports of Telnet's death have been greatly exaggerated
Terrace runs sensors attackers cannot tell from real targets. We see new attack sources first, record what they do, and ship the block rules while the attack is still running.
148
How Fast Does Claude, Acting as a User Space IP Stack, Respond to Pings?
Here is a fun thought: if we ask Claude Code to act as a user space IP stack, how quickly will it be able to respond to a ping?
149
Route leak incident on January 22, 2026
An automated routing policy configuration error caused us to leak some Border Gateway Protocol prefixes unintentionally from a router at our Miami data center. We discuss the impact and the changes we are implementing as a result.
150
From stealth blackout to whitelisting: Inside the Iranian shutdown
Iran is in the midst of one of the world’s most severe communications blackouts. This post uses Kentik data to detail how this historic event unfolded, where this event lies in the context of previous Iranian shutdowns, and finally discusses what might be in store next for Iran.