maxy

If you are considering rsync, you should also consider rclone instead, especially if you want to access cloud storage. Both are mainly for syncing in only one direction. They can be set up for two-way sync with conflict handling, but I’d consider that slightly dangerous.

Syncthing is two-way (or n-way) distributed continuous sync, devices can be offline/online at any time, and with robust conflict handling. I know it only from private use, you install it on each machine where the data lives (as opposed to accessing a cloud). It works great for that. I don’t know if it is good in a multi-user or corporate context.

I’d start with some basic Linux networking and tools, if you don’t have them already.

I don’t know if that’s the basics everyone knows these days, but… learn how TCP,UDP,ICMP,TLS relate, what a netmask is, what is ARP and MAC addresses. Fire up Wireshark and look around what is happening on your network. Learn some basic commands like ip -br -a and ss (or the older netstat) so you know how to figure out which program is listening where. Learn how to manually resolve a DNS name (dig or host). How tunnel a TCP connection or a webbrowser through ssh (port forwarding, SOCKS proxy). Learn enough of the HTTP protocol so you can manually enter a valid GET request over a simple TCP connection to port 80 with netcat or nc. Or use httpie or curl for the same purpose. You can’t host a lot with that knowledge, but it helps to figure out why things are not working.

I’d say Caddy is generally easier and a more modern alternative to Apache/nginx.

Thanks for the follow-up. Of course you would have some kind of mass-deployment, it didn’t think of that. I thought you’d maybe copy the Windows MAC to Linux, but… then you’d remember doing that.

Next up, they will also all have the same ssh host key ;-) (Which may be an advantage actually, but still confusing.) Those are the kind of problems cloud-init is solving, I guess.

Sounds like a networking exercise on its own.

Do the attempted pings show up on the wire? (Switch LEDs, network card activity light.)

Does broadcast work? (Watch if it is received with tcpdump -n on both Linux VMs, and Wireshark on the Windows hosts, while doing ping -b 10.0.0.255. Or trigger a broadcast ARP by ping-ing a non-existing IP in the same network. Those should go through all bridge and switch devices, independent of IPs and routing setup.)

I think you need four distinct MAC addresses for this setup, are they all different?

The network card/driver is filtering received unicast by MAC. I’m sure something should set up the filters correctly, but maybe it went wrong, or there is a bug in the driver. Wireshark on Windows should be able to enable promiscuous mode, which disables the filter.

Side note: I don’t think you need a crossover cable. Auto-crossover should just work these days.

At work I map a USB Ethernet device into my Linux VM when I do anything networking, exactly to avoid those kind of “is it Windows?” questions. Also, I can then check the Ethernet link at the lowest level using Linux tools like ip link or mii-tool or ethtool.

I’m using VMWare for this, which I cannot recommend any more. (It used to be good for this, but gut much worse in recent years.) I think vanilla VirtualBox doesn’t allow to map USB devices.