i have this code to read a msg from a client.

import socket

# UDP_IP = 'fd53:7cb8:383:2::10'
UDP_IP = '::'
UDP_PORT = 13400
# create socket
sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

# bind the socket
server_add = (UDP_IP, UDP_PORT)
print('starting up on {} on port {}'.format(*server_add))
sock.bind(server_add)
while True:
    print('waiting msg')
    data, addr = sock.recvfrom(1024)
    print("received message:", data)
    print("addr is", addr)
    sock.close()
    break

the client IP is : 'fd53:7cb8:383:2::c9'
the Server IP is : 'fd53:7cb8:383:2::10' 

i can saw the msg on wireshark

but the sock.recvfrom(1024) is not getting anything