Date: Mon, 1 Jun 2009 21:34:36 +0200 From: Juergen Lock <nox@jelal.kn-bremen.de> To: Jedrzej Kalinowski <kalinoj1@iem.pw.edu.pl> Cc: freebsd-emulation@freebsd.org Subject: Re: Qemu: Assigning two tap devices to one virtual machine Message-ID: <20090601193436.GA15261@triton.kn-bremen.de> In-Reply-To: <4A24180D.1090006@iem.pw.edu.pl> References: <200906011636.n51GaCbJ007208@triton.kn-bremen.de> <4A24180D.1090006@iem.pw.edu.pl>
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On Mon, Jun 01, 2009 at 08:03:57PM +0200, Jedrzej Kalinowski wrote:
> Juergen Lock pisze:
> > In article <20090523223024.GA93488@volt.iem.pw.edu.pl> you write:
> >> Hello all,
> >>
> >> I'm running qemu 0.10.5 on CURRENT machine and experienced an
> >> interesting problem.
> >>
> >> I try to run a single qemu machine with two network interfaces (tap's)
> >> connected to the same bridge - I need this for playing with m0n0wall for
> >> example.
> >>
> >> The qemu launch looks similiar to this:
> >>
> >> qemu -net nic -net tap -net nic -net tap -cdrom cdrom.iso -curses
> >>
> >> What happens is that when qemu starts up - my machine locks (sometimes I
> >> manage to kill qemu and recover it, sometimes not). I see that it's a
> >> problem with network bridge - looks like the infitine loop of arp
> >> requests that get replicated infinitely (it also kills/floods my real network
> >> that is connected through the bridge to the tap devices).
> >>
> >> My question is - have any of You tried to use multiple tap devices within
> >> one qemu machine? Can you replicate this problem in your environments?
> >>
> >> One note: there is no problem if I run two qemus and each of them has a
> >> tap device connected to bridge0. They coexist and I have no network
> >> issues in both guests. I can post qemu-if{up,down} scripts if needed.
> >
> > Ok just in case this hasn't been resolved yet...
> >
> > Try something like
> > qemu -net nic -net tap -net nic,vlan=1,macaddr=52:54:00:12:34:57 -net tap,vlan=1 -cdrom cdrom.iso -curses
> >
> > and if you want you can also add `,model=e1000' to the -net nic parameters,
> > that one (em(4) on FreeBSD) should perform a little better than the default
> > ne2kpci (ed(4) on FreeBSD.)
> >
> > Explanation: vlan= is used to associate -net nic with -net tap/user/pcap
> > connections (default is vlan=0), and macaddr= you need because qemu uses
> > one single default macaddress (52:54:00:12:34:56 atm) for all -net nic
> > and you can't have two nics with identical macs on the same network.
> >
>
> Yes, I tried it and I can confirm that it works well - assigning
> different vlans to different nics saves the day here.
>
> Also, good news is that qemu already doesn't create same MAC-addresses
> for nics blindly. I run it like this:
>
> qemu -net nic,model=e1000,vlan=0 -net user,vlan=0 -net
> nic,model=e1000,vlan=1 -net user,vlan=1
>
>
> And get:
>
> (qemu) info network
>
> VLAN 0 devices:
>
> user.0:
>
> e1000.0: model=e1000,macaddr=52:54:00:12:34:56
>
> VLAN 1 devices:
>
> user.1:
>
> e1000.1: model=e1000,macaddr=52:54:00:12:34:57
>
>
Ah so the automatic mac assignment has been fixed, even better :)
>
>
> > Good luck, :)
> > Juergen
> >
>
> Thank you for your help, Juergen (and thanks for maintainig the port the
> way it is always up to date with the latest release!)
> J??drzej Kalinowski
Thanx for the kind words...
Juergen
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