Well I tryed to change as you said but still no luck.
I'm wondering how to use strtoul function, I still havent figured out.
unsigned long strtoul (const char *__nptr, char **__endptr, int __base);
where ( ,NULL ,16 );
nptr
Null-terminated string to convert.
endptr
Pointer to character that stops scan.
base
Number base to use.
I also tryed using this:
for (byte thisByte = 0; thisByte < 4; thisByte++)
{
Serial.print(Ethernet.localIP()[thisByte], DEC);
Serial.print(".");
}