[FRDM-KL25Z(mbed)]WIZ550io Shield-A Porting Guide
WIZ550io Shield-A is arduino shield for using ethernet more easy.

Original post: http://kaizen8501.blogspot.com/2014/10/frdm-kl25zwiz550io-shield-porting-guide.html
First, it can use Digital pin 9 to 12 for SPI communication. ( 9: SCSn, 10: MOSI, 11: MISO, 12: SCLK )
Second method is using ICSP.
Software
#include "mbed.h"
#include "EthernetInterface.h"
#include "Websocket.h"
#define _DHCP
Serial pc(USBTX, USBRX); // tx, rx
int main()
{
int ret;
pc.baud(115200);
pc.printf("Start Applicationrn");
SPI spi(D11, D12, D13); // mosi, miso, sclk
EthernetInterface eth(&spi, D10, D9);//scs(D10), nRESET(PTA20)
wait(1);
#ifdef _DHCP
eth.init();
ret = eth.connect();
#else
ret = eth.init("192.168.11.10","255.255.255.0","192.168.11.1");
#endif
if(!ret)
{
pc.printf("Initialized, MAC: %srn", eth.getMACAddress());
pc.printf("Connected, IP: %s, MASK: %s, GW: %srn",
eth.getIPAddress(), eth.getNetworkMask(), eth.getGateway());
}
else
{
pc.printf("Error eth.init() - ret = %drn",ret);
return -1;
}
Websocket ws("ws://sockets.mbed.org:443/ws/demo/rw");
ws.connect();
char str[100];
for(int i=0; i<0x10; ++i) {
sprintf(str, "%d WebSocket for WIZnet W5500 Hello World over Ethernet : No Sensor", i);
ws.send(str);
// clear the buffer and wait a sec...
memset(str, 0, 100);
wait(0.5f);
// websocket server should echo whatever we sent it
if (ws.read(str)) {
pc.printf("rcv'd: %srn", str);
}
}
ws.close();
eth.disconnect();
}