msg[1]=msg[2]; msg[2]=msg[3]; msg[3]=msg[4]; msg[4]=msg[5]; msg[5]=msg[6];
Suppose you need to change the message size. Are you going to tack on a bunch more assignments? Or, are you going to learn how to use a for loop?
what I really want is to make another page to change the ip
OK.
and write the arduino
You seem to know how to do that. Although msg will need to get much bigger.
and then I send a pulse pro reset pin (using a resistor and capacitor course) at the end of the loop.
Why? All you need to do is call Ethernet.begin() again with the new value. You'll probably want to save the value in EEPROM so the Arduino can use the same value again after a reset.