+newnicnames() {
+
+ # determine predictable network names only for stretch and above
+
+ [ $do_init_tasks -eq 0 ] && return
+
+ ver=$($ROOTCMD dpkg-query --showformat='${Version}' --show udev)
+ if dpkg --compare-versions $ver lt 220-7; then
+ return
+ fi
+
+ [ -z "$NIC1" ] && return
+
+ fields="ID_NET_NAME_FROM_DATABASE ID_NET_NAME_ONBOARD ID_NET_NAME_SLOT ID_NET_NAME_PATH"
+ for field in $fields; do
+ name=$(udevadm info /sys/class/net/$NIC1 | sed -rn "s/^E: $field=(.+)/\1/p")
+ if [[ $name ]]; then
+ NIC1=$name
+ break
+ fi
+ done
+ # This condition is only needed because the nfsroot I use
+ # is based on Jessie, which has an old udev which can't
+ # figure out the persistent interface name used in stretch.
+ if ifclass VM; then NIC1=ens3; return; fi
+ if [[ ! $name ]]; then
+ echo "$0: error: could not find systemd predictable network name. Using $NIC1."
+ fi
+}
+
+if [ -z "$NIC1" ]; then
+ echo "ERROR: \$NIC1 is not defined. Cannot configure /etc/network/interfaces properly."
+fi
+newnicnames
+CIDR=$(ip -o -f inet addr show $NIC1 | awk '{print $4}')
+if ifclass DHCPC && [ $FAI_ACTION = "install" -o $FAI_ACTION = "dirinstall" ]; then
+