On Mon, 2025-01-27 at 14:54 +0100, Martin Kletzander wrote: > On Mon, Jan 27, 2025 at 12:50:05PM +0000, Iain M Conochie wrote: > > <snip> > > > > At the OS level, this network interface should get created by > > libvirt, > > so I am a bit mystified why dnsmasq is having an issue starting, as > > there is nothing using this address yet. In fact, virbr3 does not > > exist > > There might be, you can probably see an old dnsmasq listening on that > address using lsof or ss. This is a bug that is already fixed and it > could happen in various ways. > > This was fixed with a series of patches 97ed0574ea6c..d0a48eeb720f > and > is included upstream in v10.8.0. > > > until libvirt would bring up this interface: > > > > > > ifconfig -a | grep virbr > > virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 > > > > I am running libvirt 9.0.0 on Debian 12. > > > > Unfortunately that either needs to be backported or your system > updated. > But as a workaround just make sure nothing is listening on that > address, > which might need killing some dnsmasq processes. I have checked on another machine running the same version of debian, and all the interfaces are down, and no dnsmasq process are running: virsh # net-list --all Name State Autostart Persistent ------------------------------------------------------ ailsa inactive yes yes ailsatech inactive yes yes ansible inactive yes yes chef0 inactive no yes stan inactive yes yes thapxe inactive yes yes thargoid inactive yes yes vagrant-libvirt inactive no yes virsh # net-start ailsa error: Failed to start network ailsa error: internal error: Child process (VIR_BRIDGE_NAME=ailsa /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/ailsa.conf -- leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper) unexpected exit status 2: dnsmasq: failed to create listening socket for 192.168.86.1: Address already in use virsh # quit root@primus:/var/log/libvirt/qemu# ps -ef | grep dnsmas root 105994 102272 0 14:53 pts/1 00:00:00 grep dnsmas I will look into trying to get a later version of libvirt onto my system. Thanks for the pointer Martin! Iain > > > Any help or pointers greatly appreciated. > > > > Thanks! > > > > Iain > >