diff --git a/squinnondation/messages.py b/squinnondation/messages.py
index 7a228ef..56694fd 100644
--- a/squinnondation/messages.py
+++ b/squinnondation/messages.py
@@ -173,12 +173,9 @@ class HelloTLV(TLV):
             user.send_packet(sender, Packet.construct(WarningTLV.construct(
                 f"You were known as the ID {sender.id}, but you declared that you have the ID {self.source_id}.")))
             user.add_system_message(f"A client known as the id {sender.id} declared that it uses "
-                                        f"the id {self.source_id}.")
+                                    f"the id {self.source_id}.")
             sender.id = self.source_id
 
-        if self.source_id == user.id:
-            sender.marked_as_banned = True
-
         if not sender.active:
             sender.id = self.source_id  # The sender we are given misses an id
             time_hl = time.time()
diff --git a/squinnondation/peers.py b/squinnondation/peers.py
index 90c2a54..a63d7ba 100644
--- a/squinnondation/peers.py
+++ b/squinnondation/peers.py
@@ -27,7 +27,6 @@ class Peer:
         self.symmetric = False
         self.active = False
         self.errors = 0
-        self.marked_as_banned = False
 
         try:
             # Resolve DNS as an IPv6
@@ -44,7 +43,7 @@ class Peer:
 
     @property
     def potential(self) -> bool:
-        return not self.active and not self.banned
+        return not self.active and not self.banned and not isinstance(self, User)
 
     @potential.setter
     def potential(self, value: bool) -> None:
@@ -55,7 +54,7 @@ class Peer:
         """
         If a client send more than 5 invalid packets, we don't trust it anymore.
         """
-        return self.errors >= 5 or self.marked_as_banned
+        return self.errors >= 5 or isinstance(self, User)
 
     def __repr__(self):
         return self.nickname or str(self.id) or str(self.main_address)
@@ -73,12 +72,11 @@ class Peer:
         self.last_long_hello_time = max(self.last_hello_time, other.last_long_hello_time)
         self.addresses.update(self.addresses)
         self.addresses.update(other.addresses)
-        if self.main_address[1] == 1212: #always prefer the non-multicast address
+        if self.main_address[1] == 1212:  # always prefer the non-multicast address
             self.main_address = other.main_address
         elif other.main_address[1] == 1212:
             other.main_address = self.main_address
         self.id = self.id if self.id > 0 else other.id
-        self.marked_as_banned = other.marked_as_banned
         return self
 
 
@@ -105,9 +103,12 @@ class User(Peer):
             self.multicast_socket = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
             # Allows address to be reused
             self.multicast_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-            self.multicast_socket.bind(('', 1212)) #listen on all interfaces?
-            # To join the group, we need to give setsockopt a binary packed representation of the multicast group's address and on what interfaces we will listen (here all)
-            mreq = struct.pack("16s15s", socket.inet_pton(socket.AF_INET6, "ff02::4242:4242"), bytes(socket.INADDR_ANY)) #The string "16s15s" corresponds to the packing options: here it packs the arguments into a 16-byte string and a 15-byte string. 
+            self.multicast_socket.bind(('', 1212))  # listen on all interfaces?
+            # To join the group, we need to give setsockopt a binary packed representation of the multicast
+            # group's address and on what interfaces we will listen (here all)
+            mreq = struct.pack("16s15s", socket.inet_pton(socket.AF_INET6, "ff02::4242:4242"), bytes(socket.INADDR_ANY))
+            # The string "16s15s" corresponds to the packing options: here it packs the arguments into a 16-byte
+            # string and a 15-byte string.
             self.multicast_socket.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_JOIN_GROUP, mreq)
 
         self.input_buffer = ""
@@ -133,7 +134,7 @@ class User(Peer):
             curses.init_pair(i + 1, i, curses.COLOR_BLACK)
 
         # dictionnaries of neighbours
-        self.neighbours = dict()
+        self.neighbours = {self.main_address: self}
         self.nbNS = 0
         self.minNS = 3  # minimal number of symmetric neighbours a user needs to have.
 
@@ -166,14 +167,14 @@ class User(Peer):
         Translate an address into a peer. If this peer does not exist,
         creates a new peer.
         """
-        self.data_lock.acquire()
-        
         if (address, port) in self.neighbours:
             return self.neighbours[(address, port)]
+
+        self.data_lock.acquire()
         peer = Peer(address=address, port=port)
         self.neighbours[(address, port)] = peer
-        
         self.data_lock.release()
+
         return peer
 
     def find_peer_by_id(self, peer_id: int) -> Peer:
@@ -931,21 +932,25 @@ class User(Peer):
         If there is a collision with the address / the ID, then we merge clients into a unique one.
         """
         self.data_lock.acquire()
-        
+
         for addr in peer.addresses:
             if addr in self.neighbours:
                 # Merge with the previous peer
                 old_peer = self.neighbours[addr]
+                if isinstance(old_peer, User):
+                    peer, old_peer = old_peer, peer
                 peer.merge(old_peer)
             self.neighbours[addr] = peer
 
         for other_peer in list(self.neighbours.values()):
             if other_peer.id == peer.id > 0 and other_peer != peer:
                 # The peer with the same id is known as a different address. We merge everything
+                if isinstance(other_peer, User):
+                    peer, old_peer = other_peer, peer
                 peer.merge(other_peer)
                 for other_addr in peer.addresses:
                     self.neighbours[other_addr] = peer
-                
+
         self.data_lock.release()
 
     def send_neighbours(self) -> None: