Add client and server scripts to test multicast

client6.py

+import argparse
+import socket
+import struct
+import sys
+
+if not hasattr(socket, 'SO_BINDTODEVICE'):
+    socket.SO_BINDTODEVICE = 25
+
+parser = argparse.ArgumentParser()
+parser.add_argument("multicast_group", help="Multicast IPv6 to use for subscription")
+
+args = parser.parse_args()
+server_address = ('', 10000)
+
+sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
+sock.bind(server_address)
+
+# on all interfaces.
+sock.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_JOIN_GROUP, socket.inet_pton(socket.AF_INET6, args.multicast_group) + struct.pack('@I', 0))
+
+try:
+    while True:
+        data, address = sock.recvfrom(10240)
+        print(data.decode("utf-8"))
+finally:
+    sock.close()

server6.py

+import argparse
+import socket
+import struct
+import traceback
+
+parser = argparse.ArgumentParser()
+parser.add_argument("addr", help="IPv6 address to use for source")
+parser.add_argument("multicast_group", help="Multicast IPv6 address to use for destination")
+
+args = parser.parse_args()
+print(args.addr)
+print(args.multicast_group)
+
+ttl = 12
+sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
+sock.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_MULTICAST_HOPS, ttl)
+
+sock.bind((args.addr, 10000))
+try:
+    while True:
+        input_msg = input('msg --> ')
+        try:
+            sock.sendto(input_msg.encode("utf-8"), (args.multicast_group, 10000))
+        except Exception:
+            traceback.print_exc()
+            continue
+
+finally:
+    sock.close()