Just an info for those who are struggling with lwIP and PTP and NTP (SNTP = "simple" NTP), because I have it running now, after some days with SNTP working only about every 100th time or so.
I'm not a software guy, so that took me some time and nerves... For me, PCB usually stand NOT for protocol control block. ;)
PTP and NTP both use UDP, so make sure that you have enough memory pools for UDP's PCBs,
set MEMP_NUM_UDP_PCB in opt.h
to a higher value than the default 4 (in my case).
Learned a lot about lwIP...
