diff -Naur initscripts-0.7.0.3/busybox/conf.d/network initscripts-0.7.0.3-dhcp-identifier/busybox/conf.d/network
--- initscripts-0.7.0.3/busybox/conf.d/network	2015-12-09 11:21:45.882393866 +0100
+++ initscripts-0.7.0.3-dhcp-identifier/busybox/conf.d/network	2015-12-09 11:43:39.523320459 +0100
@@ -1,5 +1,5 @@
 DEFAULT_DHCP_PROG="/sbin/udhcpc"
 # -i must be the last argument!
-DEFAULT_DHCP_START="-T10 -t3 -n -x hostname:$(hostname) -i"
+DEFAULT_DHCP_START="-T10 -t3 -n -x hostname:$(hostname) -c $(dhcp-identifier $(alx-iface)) -i"
 DEFAULT_DHCP_STOP=""
 DEFAULT_NETMASK="255.255.255.0"