diff --git a/package/network/services/ppp/files/lib/netifd/ppp-down b/package/network/services/ppp/files/lib/netifd/ppp-down
index 94cefc415e..48c5325c28 100755
--- a/package/network/services/ppp/files/lib/netifd/ppp-down
+++ b/package/network/services/ppp/files/lib/netifd/ppp-down
@@ -11,3 +11,6 @@ proto_send_update "$PPP_IPPARAM"
 		[ -x "$SCRIPT" ] && "$SCRIPT" "$@"
 	done
 }
+
+# sleep 3s to wait wan_6 down
+sleep 3