lwip: Drop packets larger than MTU

components/lwip/Kconfig

@@ -84,7 +84,7 @@ menu "LWIP"
 
     config LWIP_IP_FRAG
         bool "Enable fragment outgoing IP packets"
-        default n
+        default y
         help
             Enabling this option allows fragmenting outgoing IP packets if their size
             exceeds MTU.

components/lwip/lwip

@@ -1 +1 @@
-Subproject commit 6a587ae24c6667e537f9f78d774edf3d4453d6f5
+Subproject commit 39f338547ab344e855f94eb922421036bee8e417