I've found the solution, and it's exactly as stupid and obvious as I was expecting.

The classroom computers were deployed using Clonezilla from an image that had the VirtualBox VM pre-configured. As a result of this, every VM had the same MAC address, which probably caused a lot of ARP collisions, since all the hosts and VMs were essentially on the same broadcast domain.

The solution was to simply randomize each VM's MAC address. After that, ICMP, SSH, and HTTP worked as expected. Thanks for the suggestions, but it was caused by my own oversight in the end.

(edit) I got around to reading the comments just now, @maxy@piefed.social was totally correct.

I know this isn't "selfhosting" as most people imagine it, but it is about hosting services on own hardware, hence why I'm posting in this community.

I'm supposed to help a teacher set up a networking exercise where pairs of computers are connected directly on a crossover cable and can access services (echo, HTTP, SSH, FTP) on each other. Every computer is identical: Windows 10 host, one VirtualBox VM running Linux Mint with a bridged adapter in promiscuous mode. Each host and VM has its own static link-local IP address.

The problem is, the VMs can't talk to each other, and I don't know why.

From one VM, I can ping itself, its host, and the remote host, but not the remote VM. Each host can ping itself, the local VM, the remote host, but not the remote VM. I've tried connecting both hosts to a layer-2 switch, with the same result.

Can someone point me at the one thing that I'm obviously doing wrong?

(edit) I've also tried to set the default gateway to the host's, remote host's, and remote VM's address, but nothing changed.

Running Linux on metal isn't an option. In the past, the classroom computers used to dual boot Windows and Ubuntu, but the Windows install got so bloated (the software too, not just Windows) that it needs the full SSD.

An interesting and important look at the development of Factorio's Linux-native port from an actual developer: the platform in general, Wayland, GNOME's bullshit, and dependencies.

35000 power-on hours. SMART still reports it as OK.

Time to figure out how to rebuild a RAID 5 array. The other two drives are probably nearly cooked too, but I have plenty of spares that I got for free.

Somebody accidentally deleted most of the system. There were no executables for any shells, text editors, or utilities. All they had was a single terminal that was still logged in as root. I think they had to manually type in some executable's machine code and echo it into a file.

I've been reading a lot about massive stellar objects, degenerate matter, and how the Pauli exclusion principle works at that scale. One thing I don't understand is what it means for two particles to occupy the same quantum state, or what a quantum state really is.

My background in computers probably isn't helping either. When I think of what "state" means, I imagine a class or a structure. It has a spin field, an energy_level field, and whatever else is required by the model. Two such instances would be indistinguishable if all of their properties were equal. Is this in any way relevant to what a quantum state is, or should I completely abandon this idea?

How many properties does it take to describe, for example, an electron? What kind of precision does it take to tell whether the two states are identical?

Is it even possible to explain it in an intuitive manner?

I'm getting this error that says Error. I can't tell if I fat-fingered the community name in the URL, or it got removed, or it doesn't exist in the first place, or maybe there's a legitimate issue with the software, but I hope it's useful!

I need to clarify because some people apparently never encountered the error page: it used to show the actual error. It was later changed to not do that.

(apologies for the atrocious aspect ratio)

Minecraft and Factorio ain't shit next to Conway's Game Of Life.

Low effort meme while flatpak update finishes.

I understand why having eight very specific versions of the same library is important. Doesn't mean it isn't annoying.

This image is no longer available on nasa.gov.

It's a Creative Zen Stone that I got as a Christmas gift in 2008. I just found it in a drawer, and it's still holding charge. The last thing I put on it was The Life And Times Of Scrooge by Tuomas Holopainen, in 2015 -- I don't know why, at that time I definitely had a smartphone.

It has a headphone jack, which immediately makes it better than every smartphone produced in the last several years, and it can easily drive my 80-ohm Beyerdynamic. The audio quality is as good as one can expect. The only drawback is that it only holds 1GB... my old CD rips had to be compressed to hell and back.

Let me reiterate that this has been sitting untouched for a decade and was immediately ready for action. No login, no annoying software updates, expired subscription, or remote bricking by the manufacturer. Eat my shorts, Spotify Car Thing.

P.s. A Lifetime Of Adventure is a banger. https://www.youtube.com/watch?v=JWwSVOo5K_k

LED lights are great, but I miss having a mini hot plate on my desk to mindlessly touch and burn my hand.

(Do kids even watch cartoons these days, or do they go into scrolling withdrawal before the first commercial break?)