network between host and guest

network between host and guest

[Thanasis]

I have installed kvm (app-emulation/qemu-kvm-0.12.3-r1) on linux (a
laptop with gentoo linux) and MS Windows 7 as guest.
Here is what info I get about the network on each one:
1) on linux (host):

eth0      Link encap:Ethernet  HWaddr 00:03:25:43:7f:93 
          inet addr:192.168.0.13  Bcast:255.255.255.255  Mask:255.255.255.0
          inet6 addr: fe80::203:25ff:fe43:7f93/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1492  Metric:1
          RX packets:406972 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5268868 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:132098724 (125.9 MiB)  TX bytes:7683259267 (7.1 GiB)
          Interrupt:26 Base address:0x2000

lo        Link encap:Local Loopback 
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:505 errors:0 dropped:0 overruns:0 frame:0
          TX packets:505 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:65800 (64.2 KiB)  TX bytes:65800 (64.2 KiB)

wlan0     Link encap:Ethernet  HWaddr 00:16:44:8e:5a:0b 
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

2) on the guest (sorry I could't find a way copy, so I took a screenshot):
http://i999.photobucket.com/albums/af112/aggman/Screenshot-QEMU.jpg

Question: Where is my interface on linux with IP address of 10.0.2.2 ?
The guest can actually access the internet (via the host), but where can
I see that hidden routing that linux provides to it?

PS: forgive my ignorance, I am new to kvm.

Re: network between host and guest

[Liang Guo]

在 星期一 10 5月 2010 18:46:20，Thanasis 写道：

> 
> Question: Where is my interface on linux with IP address of 10.0.2.2 ?
> The guest can actually access the internet (via the host), but where can
> I see that hidden routing that linux provides to it?
> 

I think you are using user networking(slirp) , with user networking, etch tcp 
connection is mapped to a tcp connection in host's kvm process, and  there
is no host route to the guest.  Please visit 
http://wiki.qemu.org/Documentation/Networking
for detailed information. 

-- 
Liang Guo
http://bluestone.cublog.cn

Re: network between host and guest

[Thanasis]

Probably it's slirp.
The url you provided doesn't help much though.
Thanks.

Re: network between host and guest

[Thanasis]

on 05/10/2010 09:28 PM Thanasis wrote the following:
> Probably it's slirp.
> The url you provided doesn't help much though.
>   
Anyone to provide some more help?

Re: network between host and guest

[Thanasis]

on 05/13/2010 10:48 PM dryden@sky-haven.net wrote the following:
> Ar 10.05.10 10:46, scríobh Thanasis:
>> I have installed kvm (app-emulation/qemu-kvm-0.12.3-r1) on linux (a
>> laptop with gentoo linux) and MS Windows 7 as guest.
>> Here is what info I get about the network on each one:
>> 1) on linux (host):
>
> [snip]
>
> Hi there:
>
> The precise KVM command would be useful in determining what's going on.
>
> Since I'm guessing, I may as well presume you used "-net
> nic,(options...) -net user".  If you did, the magick is in the qemu
> binary which is both providing a DHCP service to the guest and
> performing the necessary outbound source NAT.
>
> But as others have mentioned, more information on how you started KVM
> might be useful to determine what's going on.  The reason is that there
> are several ways to set up networking in KVM.
>
The command is (and running as a user, not root):

$ kvm win7kvm.img -m 1024 -boot c -usb -usbdevice tablet

$ which kvm
/usr/bin/kvm
$ ls -l /usr/bin/kvm
lrwxrwxrwx 1 root root 17 Apr 21 15:10 /usr/bin/kvm -> /usr/bin/qemu-kvm
$ file /usr/bin/qemu-kvm
/usr/bin/qemu-kvm: POSIX shell script text executable
$ cat /usr/bin/qemu-kvm
#!/bin/sh
exec /usr/bin/qemu-system-x86_64 --enable-kvm "$@"
$ file /usr/bin/qemu-system-x86_64
/usr/bin/qemu-system-x86_64: ELF 64-bit LSB executable, x86-64, version
1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.9,
stripped
$