Writing an IPv6 echo client/server

You need to write an IPv6 compliant server or client and wonder what could be the differences between an IPv6 compliant server or client and its IPv4 counterpart.

How to do it...

We use the same approach as writing an echo client/server using IPv6. The only major difference is how the socket is created using IPv6 information.

Listing 12a shows an IPv6 echo server, as follows:

#!/usr/bin/env python 
# Python Network Programming Cookbook, Second Edition -- Chapter - 3 
# This program is optimized for Python 2.7.12 and Python 3.5.2. 
# It may run on any other version with/without modifications. 
 
import argparse  
import socket 
import sys 
 
HOST = 'localhost' 
 
def echo_server(port, host=HOST): 
    """Echo server using IPv6 """ 
    for result in socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE): 
        af, socktype, proto, canonname, sa = result 
        try: 
            sock = socket.socket(af, socktype, proto...