diff --git a/src/core/udp_server.py b/src/core/udp_server.py
index c81c962..ed4a083 100644
--- a/src/core/udp_server.py
+++ b/src/core/udp_server.py
@@ -31,11 +31,16 @@ class UDPServer(asyncio.DatagramTransport):
     async def handle_datagram(self, packet, addr):
         try:
             cid = packet[0] - 1
+            if cid > config.Game['players'] * 4:
+                return
             client = self._core.get_client(cid=cid)
             if client:
                 if not client.alive:
                     client.log.debug(f"Still sending UDP data: {packet}")
                 if client._udp_sock != (self.transport, addr):
+                    self.log.debug(f"udp_addr={addr[0]}; main_addr={client.addr}")
+                    if addr[0] != client.addr:
+                        self.log.warning(f"udp_addr != main_addr. Is this bug?")
                     client._udp_sock = (self.transport, addr)
                     self.log.debug(f"Set UDP Sock for CID: {cid}")
                 await client._udp_put(packet)
diff --git a/src/core/udp_server.pyi b/src/core/udp_server.pyi
index 9757923..e449b8e 100644
--- a/src/core/udp_server.pyi
+++ b/src/core/udp_server.pyi
@@ -22,7 +22,6 @@ class UDPServer(asyncio.DatagramTransport):
         self.host = host
         self.port = port
         self.run = False
-        # self.transport: DatagramTransport = None
     def connection_made(self, transport: DatagramTransport): ...
     async def handle_datagram(self, data: bytes, addr: Tuple[str, int]):
     def datagram_received(self, data: bytes, addr: Tuple[str, int]): ...