Re: hubport connectivity problems

[lacsaP Patatetom]

Le mar. 28 mars 2023 à 09:36, Thomas Huth <thuth@redhat.com> a écrit :
>
> On 27/03/2023 21.52, Eric Nichols (DirWiz) via wrote:
> > Long time user, first time poster...
> >
> > My setup is simple.  Debian host running qemu 7.2.0 and 2 guest (Windows
> > 2010 workstation & 2022 server).  My goal is to setup a private guest only
> > network (no connection to host) with hubport.
> >
> > Based on the docs I've tried:
> > -netdev hubport,hubid=0,id=hub0 -device virtio-net-pci,netdev=hub0
> >
> > There is also the second option of:
> > -nic hubport,hubid=0,model=virtio-net-pci
> >
> > And also small mention that a hubport 0 will be setup if you just use a
> > virtual adapter and don't connect it to anything:
> > -net nic,model=virtio-net-pci,macaddr=52:54:00:00:00:03
> >
> > I did static IPs on both of the guests but can't ping or connect over TCP.
> > Any ideas?
>
> hubport basically emulates a hub *within* one instance of QEMU. Hubport
> alone does not connect to any other QEMU (i.e. guest) instance. It's mostly
> a legacy concept from the early days of QEMU - and unless you want to
> connect multiple NICs of one guest together, you likely don't need it. (see
> also https://www.qemu.org/2018/05/31/nic-parameter/ for some more 
> information).
>
> If you want to connect two local guests via a local network, you could have
> a look at the "-netdev socket" option. For example, start one QEMU with
> "-nic socket,model=virtio-net-pci,id=net0,listen=:1234" and the other QEMU
> with "-nic socket,model=virtio-net-pci,id=net1,connect=:1234" and you should
> be able to see the network traffic of one guest on the interface of the
> other and vice versa.
>
>   HTH,
>    Thomas
>
>
>
hi, if you need more than 2 guests, you can start virtual machines
connected on the same virtual network bus :

qemu \
  -drive file=hd1.img,media=disk \
  -nic socket,mac=52:54:00:11:11:11,mcast=239.192.168.1:1101
qemu \
  -drive file=hd2.img,media=disk \
  -nic socket,mac=52:54:00:22:22:22,mcast=239.192.168.1:1101
qemu \
  -drive file=hd3.img,media=disk \
  -nic socket,mac=52:54:00:33:33:33,mcast=239.192.168.1:1101

regards, lacsaP.