[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Help with tun/tap with qemu

From: Jesus M. Salvo Jr.
Subject: Re: [Qemu-devel] Help with tun/tap with qemu
Date: Wed, 11 Aug 2004 12:45:50 +1000
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.1) Gecko/20031114

Antony T Curtis wrote:

On Tue, 2004-08-10 at 16:50, Bartosz Fabianowski wrote:
So I am trying TUN/TAP.  The guest and host OS can ping each other.
However, the guest OS cannot ping any other host
If the setup on Linux is any similar to that on FreeBSD (and I am sure it is), the problem probably is routing. The guest and host are on different networks. So, you need to tell your host to forward packets to and from the guest's network. You didn't have that problem in slirp, because slirp bridges between the two networks for you, it implicitly does the forwarding.

Unfortunately, I can't tell you how to add the route under Linux due to my lack of experience with that platform.

- Bartosz

When I am using TAP on FreeBSD, I use ng_bridge so the guest is on the
same network as the host.

Info for configuring ng_bridge is in

OK, I have now setup a bridge on linux as follows.
On the host OS, I have the following script and ran it as root:

/usr/sbin/brctl addbr br0
/sbin/ifconfig eth2 promisc up
/sbin/ifconfig tap0 promisc up
/sbin/ifconfig br0 netmask broadcast up
/usr/sbin/brctl stp br0 off
/usr/sbin/brctl setfd br0 1
/usr/sbin/brctl sethello br0 1
/usr/sbin/brctl addif br0 eth2
/usr/sbin/brctl addif br0 tap0
/sbin/route add default gw

I can confirm that the host still has network connectivity using the bridge.

Now the question is, what to do on the qemu side ??
If I just run qemu as normal, qemu says:

   Connected to host network interface: tun0

... because of the /etc/qemu-ifup script on the host OS ( and of course, tun0 has an IP address )
Shouldn't qemu use tap0 as per the bridge configuration on the host OS ?
If so, how do u tell qemu to use tap0 instead of tun0 ?
Or should I change the bridge configuration to use tun0 instead of tap0 on the host OS ?

reply via email to

[Prev in Thread] Current Thread [Next in Thread]