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Date:      Thu, 20 Sep 2007 06:21:20 -0500
From:      Doug Poland <doug@polands.org>
To:        questions@freebsd.org
Subject:   QEMU and tap problems
Message-ID:  <20070920112119.GA43389@polands.org>

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Hello,

I've been following the various instructions I've found on the web in an
attempt to get tap networking with qemu-devel-0.9.0s.20070802 and
kqemu-kmod-1.3.0.p11_2 on 6.2-STABLE.

qemu was compiled with:
   _OPTIONS_READ=qemu-devel-0.9.0s.20070802
   WITH_KQEMU=true
   WITHOUT_HACKS_CIRRUS=true
   WITHOUT_RTL8139_TIMER=true
   WITHOUT_SAMBA=true
   WITH_SDL=true
   WITH_CDROM_DMA=true

The kernel modules are loaded: 
   if_tap, bridge, aio, kqemu

The sysctls are changed:
   sysctl net.link.ether.bridge_cfg=ath0,tap0
   sysctl net.link.ether.bridge.enable=1

The tap device exists:
   crw-------  1 root  wheel    0, 134 Sep 19 22:42 /dev/tap0

   tap0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet 0.0.0.0 netmask 0xff000000 broadcast 0.255.255.255
        ether 00:bd:01:3c:01:00
        Opened by PID 1317

The qemu-ifup script exists:
   cat /etc/qemu-ifup
     #!/bin/sh
     ifconfig ${1} 0.0.0.0

I launch qemu like this:
   qemu -m 512 -localtime -hda VMs/w2k3.img -net nic -net tap


Windows Server 2003 comes up.  If I attempt to use DHCP to configure the
interface in W2K3, I get a several minute pause while it attempts to
contact a DHCP server, finally it fails with the message:  
   "This connection has limited or no connectivity"
and windows assigns itself the 169.254.244.101 address.

If I try to manually configure the windows interface, i.e.,
   IP: 172.16.1.15
   NM: 255.255.255.0
   DG: 172.16.1.1
   NS: 172.16.1.17
   NS: 172.16.1.21

Windows thinks it has connectivity, but I cannot ping the default
gateway from the guest and I cannot ping the IP of the guest from the
host.

So at this point, I have no networking from the guest OS.  About the
only thing that I haven't seen on the web is people using wireless NICs
in the host.  In my case, I have an atheros chipset connected via WPA2
to my WAP.  

All help is appreciated...


-- 
Regards,
Doug



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