Hi all, I've been hoping to discover a cookbook recipe for shellscripts to create the necessary scripts for networking on the host, the necessary scripts for spawning the qemu guest, and the necessary scripts/config on the qemu guest, to make the qemu guest just another peer on my 192.168.0.0/24 LAN.
Well, that just didn't work. The Internet is full of contradictory anecdotes and guesses, most of which are series of mouseclicks rather than shellscripts. And I've ruled out VirtualBox and Gnome Boxes because I want to automate this process. For the same reason plus entangulation with dbus I've ruled out virt-manager. So like it or not, pure command line qemu is the horse I'm going to ride. For three days I've tried various combinations based on Internet writings and advice from friends, but there are just too many variables to get it exactly right. There's only one solution: I need to learn enough about bridge devices, tap devices, and VM guest networking that I can draw a block diagram of the entire networking situation, so I can intelligently probe any interaction point for troubleshooting, enabling me to intelligently narrow down the root cause of failure. Here's what *seems* to be true according to my readings: A bridge (software bridge) passes TCP packets between separate network segments (or maybe Ethernet frames???), and more importantly, although not necessarily universally true, between IP subnets. So it can pass packets between 192.168.0.0/24 and 10.0.2.0/24. So a bridge kinda-sorta-but-not-really resembles a physical network switch, in which each physical port is a software port (not to be confused with the kind of port like ssh's port 22) to which can be attached a TAP device. A TAP device is a *virtual* network *device* (I think of it as a virtual network card) that operates at OSI level 2, meaning it passes entire Ethernet frames (whereas TUN is level 3 and passes only IP packets). It can be connected to a software network bridge to communicate with everyone else. That's all I know right now, but I intend to find out more and more, until I have a complete understanding of qemu/bridge/tap/tun networking. Any knowledge anyone can give me is greatly appreciated. Thanks, SteveT Steve Litt Autumn 2020 featured book: Thriving in Tough Times http://www.troubleshooters.com/thrive _______________________________________________ Dng mailing list [email protected] https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
