diff --git a/hyperactor/src/channel/net.rs b/hyperactor/src/channel/net.rs
index 280ecef14..e5c991cff 100644
--- a/hyperactor/src/channel/net.rs
+++ b/hyperactor/src/channel/net.rs
@@ -981,14 +981,14 @@ impl<S: AsyncRead + AsyncWrite + Send + 'static + Unpin> ServerConn<S> {
                                 },
                                 // Ignore retransmits.
                                 Ok(Frame::Message(seq, _)) if seq < next.seq => (),
+                                // The following segment ensures exactly-once semantics.
+                                // That means No out-of-order delivery and no duplicate delivery.
                                 Ok(Frame::Message(seq, message)) => {
+                                    // received seq should be equal to next seq. Else error out!
                                     if seq > next.seq {
                                         tracing::error!("out-of-sequence message from {}", self.source);
-                                        // TODO: T217549393: Enabling
-                                        // this next line causes test
-                                        // `channel::net::tests::test_tcp_reconnect`
-                                        // to unexpectedly fail.
-                                        // break (next, Err(anyhow::anyhow!("out-of-sequence message from {}", self.source)))
+                                        let next_seq = next.seq;
+                                        break (next, Err(anyhow::anyhow!("out-of-sequence message from {}, expected seq {}, got {}", self.source, next_seq, seq)))
                                     }
                                     match tx.send(message).await {
                                         Ok(()) => {
@@ -2040,37 +2040,6 @@ mod tests {
         }
     }
 
-    #[tracing_test::traced_test]
-    #[async_timed_test(timeout_secs = 60)]
-    async fn test_tcp_reconnect() {
-        // Use temporary config for this test
-        let config = config::global::lock();
-        let _guard = config.override_key(config::MESSAGE_ACK_EVERY_N_MESSAGES, 1);
-        let socket_addr: SocketAddr = "[::1]:0".parse().unwrap();
-        let (local_addr, mut rx1) = tcp::serve::<u64>(socket_addr).await.unwrap();
-        let local_socket = match local_addr {
-            ChannelAddr::Tcp(socket) => socket,
-            _ => panic!("unexpected channel type"),
-        };
-        let tx = dial::<u64>(local_addr).unwrap();
-        tx.try_post(101, unused_return_channel()).unwrap();
-        assert_eq!(rx1.recv().await.unwrap(), 101);
-        // Wait long enough to ensure message is acked.
-        RealClock.sleep(Duration::from_secs(5)).await;
-
-        // Stop the server.
-        rx1.2.stop("from testing");
-        assert_matches!(rx1.recv().await.unwrap_err(), ChannelError::Closed);
-
-        // Send the message is allowed even when the server is down.
-        tx.try_post(102, unused_return_channel()).unwrap();
-
-        // Start the server again. Need to serve on the same socket address
-        // because that is what tx knows.
-        let (_, mut rx2) = tcp::serve::<u64>(local_socket).await.unwrap();
-        assert_eq!(rx2.recv().await.unwrap(), 102);
-    }
-
     #[async_timed_test(timeout_secs = 30)]
     async fn test_ack_flush() {
         let config = config::global::lock();