vmsandbox.net runs real Linux RISC-V VMs entirely in your browser. VMs can be connected by dragging wires to hubs and switches. A series of interactive labs walks through networking concepts, from a simple ping (with ARP resolution), through building a multi-router network, to constructing (and breaking) an etcd cluster. Everything is client-side and isolated, allowing quick and safe experimentation.

https://github.com/vmsandbox-net/vmsandbox