diff --git a/ouroboros-network-framework/src/Simulation/Network/Snocket.hs b/ouroboros-network-framework/src/Simulation/Network/Snocket.hs
index 1f965ef765e..618055726a2 100644
--- a/ouroboros-network-framework/src/Simulation/Network/Snocket.hs
+++ b/ouroboros-network-framework/src/Simulation/Network/Snocket.hs
@@ -95,7 +95,7 @@ stepScriptSTM scriptVar = do
     return x
 
 
-data Connection m = Connection
+data Connection m addr = Connection
     { -- | Attenuated channels of a connection.
       --
       connChannelLocal  :: !(AttenuatedChannel m)
@@ -109,6 +109,10 @@ data Connection m = Connection
       -- open.
       --
     , connState         :: !ConnectionState
+
+      -- | Provider of this Connection, so one can know its origin and decide
+      -- accordingly when accepting/connecting a connection.
+    , connProvider      :: !addr
     }
 
 
@@ -132,7 +136,7 @@ data ConnectionState
   deriving (Eq, Show)
 
 
-dualConnection :: Connection m -> Connection m
+dualConnection :: Connection m addr -> Connection m addr
 dualConnection conn@Connection { connChannelLocal, connChannelRemote } =
     conn { connChannelLocal  = connChannelRemote
          , connChannelRemote = connChannelLocal
@@ -149,7 +153,7 @@ mkConnection :: ( MonadLabelledSTM   m
                                    (SnocketTrace m (TestAddress addr)))
              -> BearerInfo
              -> ConnectionId (TestAddress addr)
-             -> STM m (Connection m)
+             -> STM m (Connection m (TestAddress addr))
 mkConnection tr bearerInfo connId@ConnectionId { localAddress, remoteAddress } = do
     (channelLocal, channelRemote)  <-
       newConnectedAttenuatedChannelPair
@@ -176,6 +180,7 @@ mkConnection tr bearerInfo connId@ConnectionId { localAddress, remoteAddress } =
                         channelRemote
                         (biSDUSize bearerInfo)
                         SYN_SENT
+                        localAddress
 
 
 -- | Connection id independent of who provisioned the connection. 'NormalisedId'
@@ -209,7 +214,7 @@ data NetworkState m addr = NetworkState {
 
       -- | Registry of active connections.
       --
-      nsConnections       :: StrictTVar m (Map (NormalisedId addr) (Connection m)),
+      nsConnections       :: StrictTVar m (Map (NormalisedId addr) (Connection m addr)),
 
       -- | Get an unused ephemeral address.
       --
@@ -448,7 +453,7 @@ data FD_ m addr
     -- assigned to it.  This corresponds to 'SYN_SENT' state.
     --
     | FDConnecting !(ConnectionId addr)
-                   !(Connection m)
+                   !(Connection m addr)
 
     -- | 'FD_' for snockets in connected state.
     --
@@ -458,7 +463,7 @@ data FD_ m addr
     | FDConnected
         !(ConnectionId addr)
         -- ^ local and remote addresses
-        !(Connection m)
+        !(Connection m addr)
         -- ^ connection
 
     -- | 'FD_' of a closed file descriptor; we keep 'ConnectionId' just for
@@ -982,9 +987,14 @@ mkSnocket state tr = Snocket { getLocalAddr
           let connId = ConnectionId localAddress (cwiAddress cwi)
 
           case Map.lookup (normaliseId connId) connMap of
-             Nothing                          -> return False
-             Just (Connection _ _ _ SYN_SENT) -> return True
-             _                                -> return False
+             Nothing                                     ->
+               return False
+             Just (Connection _ _ _ SYN_SENT provider) ->
+               return ( provider /= localAddress
+                     || localAddress == cwiAddress cwi
+                      )
+             _                                           ->
+               return False
 
         accept_ = Accept $ \unmask -> do
             bracketOnError
@@ -1062,6 +1072,7 @@ mkSnocket state tr = Snocket { getLocalAddr
                                             , connChannelRemote = channelRemote
                                             , connSDUSize       = sduSize
                                             , connState         = ESTABLISHED
+                                            , connProvider      = remoteAddress
                                             })
 
                     traceWith tr (WithAddr (Just (localAddress connId)) Nothing