Re: [Qemu-devel] NETDEV WATCHDOG: eth0: transmit timed out

[Jim C. Brown]

On Wed, Jan 05, 2005 at 09:06:31PM +0100, Horst Schlonz wrote:
> > Show us what is in your /etc/qemu-ifup script.
> > 
> address@hidden # cat /etc/qemu-ifup
> #!/bin/sh
> sudo -p "Password for $0:" /sbin/ifconfig $1 172.20.0.1
> address@hidden #

Yes, you are missing the iptables lines. (Personally I prefer ipchains to
iptables, but alas ...)

(the following script was "borrowed" from 
http://www.scaramanga.co.uk/stuff/qemu-ifup)

--CUT HERE--
#!/bin/sh

## Setup your guest OS with the following parameters
## IP - 192.168.1.1
## Mask - 255.255.255.0
## Gateway - 192.168.1.254
## DNS - whatver is in your resolv.conf

# Remember to have the following in sysctl.conf and do sysctl -p
# net.ipv4.ip_forward = 1

# Set these to the IP/mask you want to your qemu vm to have on the network
qemu_ip="152.78.192.217"
qemu_netmask="255.255.252.0"

# Setup an interface for the vm to use
ifconfig eth0:1 up $qemu_ip netmask $qemu_netmask

# Clear iptables
iptables -t nat -F PREROUTING
iptables -t nat -F POSTROUTING

# Setup NAT
iptables -t nat -A PREROUTING -d $qemu_ip \
        -j DNAT --to-destination 192.168.1.1
iptables -t nat -A POSTROUTING -s 192.168.1.1 \
        -j SNAT --to-source $qemu_ip

# Bring up the TUN interface
sudo -p "Password for $0:" /sbin/ifconfig $1 192.168.1.254
--CUT HERE--

can you test out that script and see if it works?

> > That isn't good enough, you need to add several rules to get it to work.
> > 
> 
> i just followed the documentation:
> 
> quote
> 3.7.1 Using tun/tap network interface
> This is the standard way to emulate network. QEMU adds a virtual network
> device on your host (called tun0), and you can then configure it as if
> it was a real ethernet card.
> 
> As an example, you can download the `linux-test-xxx.tar.gz' archive and
> copy the script `qemu-ifup' in `/etc' and configure properly sudo so
> that the command ifconfig contained in `qemu-ifup' can be executed as
> root. You must verify that your host kernel supports the TUN/TAP network
> interfaces: the device `/dev/net/tun' must be present.
> /quote
> 

Did you copy the qemu-ifup script from the one in linux-test-xxx.tar.gz?
I've never looked at it (since I use VDE) but I'd be suprised if that script
contained only what you showed me.

-- 
Infinite complexity begets infinite beauty.
Infinite precision begets infinite perfection.