Re: KVM networking.
Thank You for Your time and answer, Arno:
>Sthu Deus (firstname.lastname@example.org on 2011-11-08 14:44 +0700):
>> >> /usr/bin/kvm -localtime -m 256 -no-reboot
>> >> -cdrom ./debian-220.127.116.11-amd64-netinst/debian-18.104.22.168-amd64-netinst.iso
>> >> -boot d -hda ./da -net nic -net tap,ifname=tap0,script=no
>> >> kvm: -net tap,ifname=tap0,script=no: could not
>> >> configure /dev/net/tun (tap0): Operation not permitted
>> 1. The bridges take the Internet connections for itself - thus
>> leaving the host app.s w/o Internet access, probably routing needed
>> here - but they do not make any specifications for that.
>That sounds weird. What does brctl show? A default setup with these two
>lines should already work fine:
>iface br0 inet dhcp
> bridge_ports eth0
>Just remember to leave eth0 unconfigured...
Then how do host's app.s will get to Internet?
>> 2. As a workstation - it does not provide access from host to the
>You mean networking access? I've never needed it, but it should work
>once your host apps have networking access... (just tested: ping
>between host and vm works fine for me).
I mean that DHCP of KVM gives Internet access to guest and having no
interface from host to guest, I can not reach the guest from host. Of
course, host app.s and guest's app.s - both have Internet connection,
but not host-guest connection.
>> 3. W/ tap - You have seen already the problem - some unknown to me
>> permission problem - do You know why is it so?
>I can make a guess:
>$ ls -l /dev/net/tun
>crw-rw---- 1 root kvm 10, 200 Nov 9 21:36 tun
crw-rw-rw- 1 root root 10, 200 Nov 11 11:44 /dev/net/tun
>aschuring users kvm [..]
>$ /usr/sbin/tunctl -b
>TUNSETIFF: Operation not permitted
>$ sudo setcap cap_net_admin+ep /usr/sbin/tunctl
>$ /usr/sbin/tunctl -b
We have discussed w/ You already that this is not the solution we are
looking for. :)
>Yes. You can just add tunctl to your list of sudo commands, and use the
>output of ifname=$(sudo tunctl -b -u $(whoami)) on the kvm command
>line. Alternatively, set the cap_net_admin capability on tunctl and you
>won't need sudo (but still upgrade-unsafe)...
>This way, kvm will not need to create the interface and you won't run
>into permission problems.
Now it works - regarding the permission problem, but I need the
Of course I can create by root w/:
ifconfig tap0 192.168.1.1 up
route add -host 192.168.1.1 dev tap0
but I want w/o root.
And even w/ root - I still can not get network working between host and
guest - having configured guest w/:
iface eth0 inet static
# dns-* options are implemented by the resolvconf package, if installed