LPC1788, LwIP, reassembly problem

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by FlySnake on Sun Jul 14 05:28:39 MST 2013
Hi, everyone
I've got a problem with LwIP (with lpcopen) and LPC1788

ping -s 1473
PING ( 1473(1501) bytes of data.
1481 bytes from icmp_req=1 ttl=255 time=1.02 ms
From icmp_seq=2 Frag reassembly time exceeded

With ICMP echo request of size below 1473 bytes - all is OK. But with 1473+ packet is fragmented on IP layer and it causes a problem.

mem_malloc: could not allocate 1552 bytes

There is a mention about this problem http://www.lpcware.com/content/bugtrackerissue/lwiplpc-lpc17emac-driver-fault-exception-several-conditions but the suggested code didn't help and it seems like nobody cares about this bug.
The port from http://www.freertos.org/FreeRTOS-Plus/FreeRTOS_Plus_IO/Demo_Applications/LPCXpresso_LPC1769/NXP_LPC1769_Demo_Description.shtml works fine.