cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto enp1s0
iface enp1s0 inet manual
# br0 for kvm
auto br0
iface br0 inet dhcp
hwaddress ether 00:11:32:4F:B2:54
bridge_ports enp1s0
bridge_maxwait 0
bridge_fd 0
bridge_stp off