# Debian 12
$ apt install lxc
# /etc/network/interfaces
auto br0
iface br0 inet static
address x.x.x.x/24
gateway x.x.x.x.x
bridge-ports enp6s18
bridge-stp off
bridge-fd 0
# /etc/default/lxc-net
USE_LXC_BRIDGE="false"
$ ip link set dev lxcbr0 down
$ brctl delbr lxcbr0
$ brctl show
lxc-create -n d12 -t debian
# /var/lib/lxc/d12/config
lxc.net.0.link = br0
$ lxc-stop d12
$ lxc-start d12
$ lxc-ls -f