Norbert,
Thank's, I found it and used it, but it did not solved my problem. But may be I'm in the wrong direction. My problem is that I loose some ping randomly, so I tried to investigate, and searched where are done ping response. Are they done by uIP or by the enc28J60 directly ?
This is very strange, because even with a sketch doing nothing in the main loop (echoserver sample), I loose some ping packet (may be 1 every 50/100 packet).
So I tried ethercard library just to test (spent time to understand that I needed to set CS pin to pin 10 at init because by default it use digital pin 8 ) and then tried the ethernode ino file. No problem, ping are consistent. After I changed the refresh value so my browser will always query the ethercard stack with web server on. Of course after this change, ping varied from 1ms to 50ms but this is normal the app is really stressed (and debug info sent on Arduino Serial) in this case, but I never lost a ping.
Did you encounter this kind of problem ? My desktop and Arduino are located on same cisco switch, I will try to ping from linux computer to be sure, not really always trusting TCP/IP microsoft stack, sometimes I saw strange things.
For the Rest API tried some but I'm writing my own, lot of them used official ethernet shield not the enc28j60 so not the same "process". So instead spending time to search and adapt, I decided to write quickly mine, very basic and simple.