diff --git a/squinnondation/messages.py b/squinnondation/messages.py
index 2b15993..a5304f7 100644
--- a/squinnondation/messages.py
+++ b/squinnondation/messages.py
@@ -120,7 +120,7 @@ class PadNTLV(TLV):
 
     def handle(self, squirrel: Any, sender: Any) -> None:
         # TODO Add some easter eggs
-        squirrel.add_system_message(f"I received {self.length} zeros, am I so a bag guy ? :cold_sweat:")
+        squirrel.add_system_message(f"I received {self.length} zeros, am I so a bad guy ? :cold_sweat:")
 
     @staticmethod
     def construct(length: int) -> "PadNTLV":
@@ -201,6 +201,11 @@ class NeighbourTLV(TLV):
     ip_address: IPv6Address
     port: int
 
+    def validate_data(self) -> bool:
+        if not (1 <= self.port <= 65535):
+            raise ValueError(f"Invalid port received in NeighbourTLV: {self.port}")
+        return True
+
     def unmarshal(self, raw_data: bytes) -> None:
         self.type = raw_data[0]
         self.length = raw_data[1]
@@ -259,7 +264,6 @@ class DataTLV(TLV):
     def handle(self, squirrel: Any, sender: Any) -> None:
         """
         A message has been sent. We log it.
-        TODO: Check that the tuple (sender_id, nonce) is unique to avoid duplicates.
         """
         msg = self.data.decode('UTF-8')