Hi Peter, I'm assuming you're also using dynamically created "tap" interfaces in your setup. That is, when QEMU starts it's creating a tap interface to funnel Ethernet traffic to and from the guest...so a command line something like
-netdev type=tap,id=testnet,script="./qemu-tap-up",downscript="./qemu-tap-down" You can do routing, but you would still need to use a bridge interface for the dynamically created "tap" interface to connect to!! It's just that rather than setting up the bridge interface to do bridging between the tap and the "real" ethernet of the host, you'd set up the bridge interface to be a separate routed interface on your host. Routing is a bit more difficult to setup than simple bridging because you have to first make sure your host is configured for routing (most aren't by default) and then you have to make sure your "real" networking infrastructure knows about the new QEMU guest subnet and how to route to it (via your host). See the following URL for an example script to run when your QEMU tap interface is created that allows routing and you'll see how much extra effort it is to get routing (in this case with NAT) working compared to simple bridging. https://wiki.qemu.org/Documentation/Networking/NAT If you just want QEMU to do simple NAT between the guest and the "real" network then just use "SLIRP" as per https://wiki.qemu.org/Documentation/Networking#User_Networking_.28SLIRP.29 (I haven't tested it...I always use tap and bridging) Good luck! On Tue, 16 Mar 2021, at 15:34, [email protected] wrote: > Hi, > > Every mention of a network connection I've seen involves a bridge. Is > a bridge necessary? If so, why? Why not route to the guest, analogous > to routing to a machine on a subnet connected by an Ethernet cable? > > Thx, ... Peter E. > > -- > cell: +1 236 464 1479 Bcc: peter at easthope. ca > VoIP: +1 604 670 0140 > > >
