diff --git a/common/linux_iphelper.sh b/common/linux_iphelper.sh
index e22f91a..e29ceb3 100644
--- a/common/linux_iphelper.sh
+++ b/common/linux_iphelper.sh
@@ -125,3 +125,13 @@ resolve_lower_devices()
 		}
 	}
 }
+
+default_route_interfaces6()
+{
+	sed -nre 's/^00000000000000000000000000000000 00 [0-9a-f]{32} [0-9a-f]{2} [0-9a-f]{32} [0-9a-f]{8} [0-9a-f]{8} [0-9a-f]{8} [0-9a-f]{8} +(.*)$/\1/p' /proc/net/ipv6_route | grep -v lo | sort -u | xargs
+}
+
+default_route_interfaces4()
+{
+	sed -nre 's/^([^\t]+)\t00000000\t[0-9A-F]{8}\t[0-9A-F]{4}\t[0-9]+\t[0-9]+\t[0-9]+\t00000000.*$/\1/p' /proc/net/route | sort -u | xargs
+}