fix: add accept of broadcast messages

ethernet.py

@@ -48,7 +48,9 @@ def receive_message(interface, receive_all):
         message = s.recv(MessageFrame.len())
         message = MessageFrame.from_hex(message)
         breakpoint()
-        if receive_all or message.dest == getHwAddr(interface):
+        if (receive_all
+                or message.dest == getHwAddr(interface)
+                or message.dest == '000000000000'):
             print(message)
         else:
             print("nomesg")