diff --git a/TheengsGateway/__init__.py b/TheengsGateway/__init__.py
index ece2e39..2846a82 100644
--- a/TheengsGateway/__init__.py
+++ b/TheengsGateway/__init__.py
@@ -19,6 +19,7 @@
 """
 
 import sys
+import uuid
 from pathlib import Path
 
 from .ble_gateway import run
@@ -48,6 +49,12 @@ def main() -> None:
     if configuration["discovery_topic"].endswith("/sensor"):
         configuration["discovery_topic"] = configuration["discovery_topic"][:-7]
 
+    # Get the MAC address of the gateway.
+    mac_address = uuid.UUID(int=uuid.getnode()).hex[-12:]
+    configuration["gateway_id"] = ":".join(
+        [mac_address[i : i + 2] for i in range(0, 12, 2)]
+    ).upper()
+
     if not configuration["host"]:
         sys.exit("MQTT host is not specified")
 
diff --git a/TheengsGateway/ble_gateway.py b/TheengsGateway/ble_gateway.py
index 0c8b3dd..74e58f0 100644
--- a/TheengsGateway/ble_gateway.py
+++ b/TheengsGateway/ble_gateway.py
@@ -151,6 +151,7 @@ def on_connect(
                     retain=True,
                 )
                 self.subscribe(self.configuration["subscribe_topic"])
+                self.subscribe("theengs/internal")
             else:
                 logger.error(
                     "Failed to connect to MQTT broker %s:%d reason code: %s",
@@ -226,28 +227,43 @@ def subscribe(self, sub_topic: str) -> None:
         """Subscribe to MQTT topic <sub_topic>."""
 
         def on_message(client, userdata, msg) -> None:  # noqa: ANN001,ARG001
-            logger.info(
-                "Received `%s` from `%s` topic",
-                msg.payload.decode(),
-                msg.topic,
-            )
-            try:
-                msg_json = json.loads(msg.payload.decode())
-            except (json.JSONDecodeError, UnicodeDecodeError) as exception:
-                logger.warning(
-                    "Invalid JSON message %s: %s", msg.payload.decode(), exception
-                )
-                return
+            # evaluate tracker sync message
+            if msg.topic == "theengs/internal/trackersync":
+                msg_json = json.loads(msg.payload)
+                logger.info("trackersync message: %s", msg_json)
+
+                if (
+                    msg_json["gatewayid"] != self.configuration["gateway_id"]
+                    and msg_json["tracker"] in self.discovered_trackers
+                ):
+                    self.discovered_trackers[msg_json["tracker"]].time = 0
+                    logger.info("Tracker %s disassociated", msg_json["tracker"])
+
+                logger.info("Discovered Trackers: %s", self.discovered_trackers)
 
-            try:
-                msg_json["id"] = self.rpa2id(msg_json["id"])
-            except KeyError:
-                logger.warning(
-                    "JSON message %s doesn't contain id", msg.payload.decode()
+            else:
+                logger.info(
+                    "Received `%s` from `%s` topic",
+                    msg.payload.decode(),
+                    msg.topic,
                 )
-                return
+                try:
+                    msg_json = json.loads(msg.payload.decode())
+                except (json.JSONDecodeError, UnicodeDecodeError) as exception:
+                    logger.warning(
+                        "Invalid JSON message %s: %s", msg.payload.decode(), exception
+                    )
+                    return
+
+                try:
+                    msg_json["id"] = self.rpa2id(msg_json["id"])
+                except KeyError:
+                    logger.warning(
+                        "JSON message %s doesn't contain id", msg.payload.decode()
+                    )
+                    return
 
-            self.decode_advertisement(msg_json)
+                self.decode_advertisement(msg_json)
 
         self.client.subscribe(sub_topic)
         self.client.on_message = on_message
@@ -392,7 +408,7 @@ def check_tracker_timeout(self) -> None:
                 )
                 time_model.time = 0
                 self.discovered_trackers[address] = time_model
-                logger.debug("Discovered Trackers: %s", self.discovered_trackers)
+                logger.info("Discovered Trackers: %s", self.discovered_trackers)
 
     async def ble_scan_loop(self) -> None:
         """Scan for BLE devices."""
@@ -614,7 +630,7 @@ def publish_json(
                 round(time()),
                 str(data_json["model_id"]),
             )
-            logger.debug("Discovered Trackers: %s", self.discovered_trackers)
+            logger.info("Discovered Trackers: %s", self.discovered_trackers)
 
         # Remove "track" if PUBLISH_ADVDATA is 0
         if not self.configuration["publish_advdata"] and "track" in data_json:
diff --git a/TheengsGateway/discovery.py b/TheengsGateway/discovery.py
index 69ca8c4..b5543d0 100644
--- a/TheengsGateway/discovery.py
+++ b/TheengsGateway/discovery.py
@@ -272,8 +272,17 @@ def copy_pub_device(self, device: dict) -> dict:
             self.discovered_trackers[device["id"]] = TnM(
                 round(time()), device["model_id"]
             )
-            logger.debug("Discovered Trackers: %s", self.discovered_trackers)
 
+            # publish tracker sync message
+            message = json.dumps(
+                {"gatewayid": self.configuration["gateway_id"], "tracker": device["id"]}
+            )
+            self.publish(
+                message,
+                "theengs/internal/trackersync",
+            )
+
+            logger.debug("Discovered Trackers: %s", self.discovered_trackers)
         pub_device_copy = device.copy()
         # Remove "track" if PUBLISH_ADVDATA is 0
         if not self.configuration["publish_advdata"] and "track" in pub_device_copy: