Trying to declare an IP using a variable

The ip is a 4 byte array variable. Try something like this:

Serial.print(ip[0],DEC);
Serial.print(".");
Serial.print(ip[1],DEC);
Serial.print(".");
Serial.print(ip[2],DEC);
Serial.print(".");
Serial.println(ip[3],DEC);

You could use a loop if you wanted to be cleaner.