how to change dhcp range for default virbr0

[Gianluca Cecchi]

Hello,
I want to make the default network assign ips in the range of
192.168.122.101 - 192.168.122.254 instead than default values.

> From virt-manager it seems that the setting is not editable.
Changing the file /etc/libvirt/qemu/networks/default.xml and restarting
libvirtd and/or the system it seems the file actually is not parsed as I
see:
[root@tekkaman ~]# ps -ef|grep dns
nobody    1464     1  0 18:59 ?        00:00:00 /usr/sbin/dnsmasq
--strict-order --bind-interfaces
--pid-file=/var/run/libvirt/network/default.pid --conf-file=
--listen-address 192.168.122.1 --except-interface lo --dhcp-range
192.168.122.2,192.168.122.254 --dhcp-lease-max=253

and the same range in virt-manager networks window....

Is there a method to change behaviour so that in default virbr0 I have s
subset of fixed ip and a subset of dhcp assigned ones?

Using F12 + rawvirt repository
libvirt-0.7.6-1.fc12.x86_64

Thanks,
Gianluca

[Laine Stump]

On 03/01/2010 02:35 PM, Gianluca Cecchi wrote:
>  Hello,
>  I want to make the default network assign ips in the range of 
>  192.168.122.101 - 192.168.122.254 instead than default values.
>
>  From virt-manager it seems that the setting is not editable. 
I'm not sure why all the info is displayed in a nice dialog tab in 
virt-manager, but the fields are all read-only - maybe the backend  
isn't implemented yet.

However, you can easily edit it from the shell - "virsh net-edit 
default" will bring up the XML config in your editor of choice (whatever 
"EDITOR" is set to in the environment, or vi by default). Just change 
the range, exit the editor, then run:

     virsh net-destroy default
     virsh net-start default

(until you restart the network, the dnsmasq process will still have the 
old config). Also, I notice that virt-manager will retain the 
out-of-date config info (even though the new config has taken effect) 
until you disconnect and reconnect.

>  Changing the file /etc/libvirt/qemu/networks/default.xml and 
>  restarting libvirtd and/or the system it seems the file actually is 
>  not parsed as I see: 
You should not directly edit these files. Always edit via virsh 
commands, or any other application that uses the libvirt API.

>  [root@tekkaman ~]# ps -ef|grep dns
>  nobody    1464     1  0 18:59 ?        00:00:00 /usr/sbin/dnsmasq 
>  --strict-order --bind-interfaces 
>  --pid-file=/var/run/libvirt/network/default.pid --conf-file=  
>  --listen-address 192.168.122.1 --except-interface lo --dhcp-range 
>  192.168.122.2,192.168.122.254 --dhcp-lease-max=253
>
>  and the same range in virt-manager networks window....
>
>  Is there a method to change behaviour so that in default virbr0 I have 
>  s subset of fixed ip and a subset of dhcp assigned ones?
>
>  Using F12 + rawvirt repository
>  libvirt-0.7.6-1.fc12.x86_64
>
>  Thanks,
>  Gianluca
>
>
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>  virt mailing list
>  virt(a)lists.fedoraproject.org
>  https://admin.fedoraproject.org/mailman/listinfo/virt

[Gianluca Cecchi]

On Mon, Mar 1, 2010 at 9:09 PM, Laine Stump <laine(a)redhat.com&gt; wrote:

>  [snip]
>  
Just change the range, exit the editor, then run:
>      virsh net-destroy default
>      virsh net-start default
>
>  (until you restart the network, the dnsmasq process will still have the old
>  config). Also, I notice that virt-manager will retain the out-of-date config
>  info (even though the new config has taken effect) until you disconnect and
>  reconnect.
>
>
>  
Ok. It worked, thanks.
I had no guests configured at this moment, so no problem.
But what would have been the impact in case of running guests that were
using this network?
Link down/link up?
Or nothing at all, but only problems with new guests asking for an ip not
getting one?

Gianluca