diff --git a/Samples/Universal/interfaces b/Samples/Universal/interfaces
index 8d1fb2360..03e8d8257 100644
--- a/Samples/Universal/interfaces
+++ b/Samples/Universal/interfaces
@@ -9,4 +9,4 @@
 ###############################################################################
 #ZONE	INTERFACE	BROADCAST	OPTIONS
 -	lo		-		ignore
-net	all		-		dhcp,physical=+,routeback
+net	all		-		dhcp,physical=+,routeback,optional