internal error: Network is already in use by interface virbr0

[Michael Ströder]

On 9/17/21 18:46, Laine Stump wrote:
> On 9/17/21 7:11 AM, Michael Ströder wrote:
>> I'm using libvirt 7.7.0 on openSUSE Tumbleweed.
>>
>> Until recently everything just worked. But now my virtual NAT network is
>> not usable anymore.
>> [..]
>> # virsh net-start vnet1
>> error: Failed to start network vnet1
>> error: internal error: Network is already in use by interface virbr0
> 
> Someone else (probably libvirt itself, for libvirt's "default" network)
> has created a bridge device called virbr0, and has set it up on the same
> subnet that you are trying to use for your network, which is confusingly
> called "vnet1".

Many thanks for pointing me into the right direction. The culprit was an
interface definition in NetworkManager's config. Not sure whether I had
added it myself months/years ago or not.

After removing it and rebooting(!) everything seems to work as expected.

Thanks again!

Ciao, Michael.