First, we need to configure the data to connect to the server and send initial data to the server:

client = socket.socket (socket.AF_INET6, socket.SOCK_STREAM)
client.connect ((host, port))

message = "Hello from ipv6 client"
print ("Send data to server: %s" %message)
client.send(bytes(message.encode('utf-8')))
data = client.recv(4096)
print ('Received initial message from server:', data.decode())

Then, we will create a loop and use the send and recv methods from the socket client to transmit information from the client to the server. We use the exit message to close the connection between the client and server.

You can find the following code in the echo_client_ipv6.py file:

#!/usr/bin/env python3

import argparse
import socket

IPV6_ADDRESS = '::1'

def echo_client_ipv6(port, host=IPV6_ADDRESS):
    # Configure the data to connect to the server
    # socket.AF_INET6 to indicate that we will use Ipv6
    # socket.SOCK_STREAM to use TCP/IP
    # These protocols must be the same as on the server
    try:
        client = socket.socket (socket.AF_INET6, socket.SOCK_STREAM)
        client.connect ((host, port))
        print ("Connected to the server --->% s:% s"% (host, port))
    except socket.error as err:
        print ("Socket error:%s" %err)
        client.close()
    
    # send initial data to server
    message = "Hello from ipv6 client"
    print ("Send data to server: %s" %message)
    client.send(bytes(message.encode('utf-8')))
    data = client.recv(4096)
    print ('Received initial message from server:', data.decode())

If we continue analyzing the code, we can see how our infinite loop requests the introduction of messages and commands that are entered by the user to send them to the server:

    while True:
        message = input("Write your message > ")
        client.send(bytes(message.encode('utf-8')))
        data = client.recv(4096)
        print ('Received from server:', data.decode())
        if data.decode() == "exit":
            break;
        command = input("Write your command > ")
        command = "command/"+command
        client.send(bytes(command.encode('utf-8')))
        data = client.recv(4096)
        print ('Received command server:', data.decode())

    print("------- CLOSE CONNECTION ---------")
    client.close()
 
if __name__ == '__main__': 
    parser = argparse.ArgumentParser(description='IPv6 socket client')
    parser.add_argument('--port', action="store", dest="port", type=int, required=True)
    given_args = parser.parse_args()
    port = given_args.port
    echo_client_ipv6(port)