Index: linux-source-4.19/include/uapi/linux/hdlc.h
===================================================================
--- linux-source-4.19.orig/include/uapi/linux/hdlc.h
+++ linux-source-4.19/include/uapi/linux/hdlc.h
@@ -13,7 +13,7 @@
 #define _UAPI__HDLC_H
 
 
-#define HDLC_MAX_MTU 1500	/* Ethernet 1500 bytes */
+#define HDLC_MAX_MTU 1700	/* Ethernet 1500 bytes */
 #if 0
 #define HDLC_MAX_MRU (HDLC_MAX_MTU + 10 + 14 + 4) /* for ETH+VLAN over FR */
 #else