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.