Create a file /etc/qemu-ifup that contain:
#!/bin/sh sudo modprobe tun sudo /sbin/ifconfig $1 up 10.0.2.2 netmask 255.255.255.0 broadcast 10.0.2.255 # IP masquerade sudo echo "1" > /proc/sys/net/ipv4/ip_forward sudo /sbin/iptables -N nat sudo /sbin/iptables -t nat -F sudo /sbin/iptables -t nat -A POSTROUTING -s 10.0.2.15 -j MASQUERADE sudo /sbin/iptables -t nat -A POSTROUTING -d 10.0.2.15 -o $1
Don’t forget to give it execution permissions:
chmod 755 /etc/qemu-ifup
Start qemu with the following parameters:
qemu /home/kevin/qemu-mdk10.1.img -n /etc/qemu-ifup
Setup the network in your ghest OS in qemu:
ifconfig eth0 10.0.2.15 route add default gw 10.0.2.2
Test the visibility of the guest OS from the host OS:
[root@localhost kevin]# ping 10.0.2.15 PING 10.0.2.15 (10.0.2.15) 56(84) bytes of data. 64 bytes from 10.0.2.15: icmp_seq=1 ttl=64 time=2.96 ms 64 bytes from 10.0.2.15: icmp_seq=2 ttl=64 time=0.295 ms 64 bytes from 10.0.2.15: icmp_seq=3 ttl=64 time=0.296 ms --- 10.0.2.15 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2000ms rtt min/avg/max/mdev = 0.295/1.185/2.965/1.258 ms
Test the visibility of the host from the guest:
[root@localhost root]# ping 10.0.2.2 PING 10.0.2.2 (10.0.2.2) 56(84) bytes of data. 64 bytes from 10.0.2.2: icmp_seq=1 ttl=64 time=1.08 ms 64 bytes from 10.0.2.2: icmp_seq=2 ttl=64 time=0.433 ms 64 bytes from 10.0.2.2: icmp_seq=3 ttl=64 time=0.383 ms --- 10.0.2.2 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2001ms rtt min/avg/max/mdev = 0.383/0.634/1.087/0.321 ms
Wow, I’ve been trying to get QEMU to recognize my network for a couple days, and your script, though very old, finally worked. I had to put in different options, my QEMU looks like this:
THANK YOU! I’ll definitely be linking to this post when I blog about my success.
Hi Joel !
Happy to see that some old knowledge can be recycled !
That works good but how can I add another guest? I want to create a small virtual LAN.
Hi daniele,
I’m sorry, I never tried to launch several guests. I don’t know how my script will behave.
If you manage to make a more generic script to support many guests, feel free to comments about your experimentations !
This post was written with qemu 0.7.x. As Joel said above, with a recent version (0.8.x in this case), you have to launch qemu with the following command:
You can also add
-m 512parameter if you need qemu to emulate 512 Mb of RAM.hi
I have apache installed on localhost for testing/development purposes and want access localhost on host machine from quest qemu. But I don’t want qemu to access network. Just a localhost on the host machine.
Can you please explain how to do this?