diff --git a/connections/implementation/mediums/ble_v2/BUILD b/connections/implementation/mediums/ble_v2/BUILD
index 02dafdfd..759273be 100644
--- a/connections/implementation/mediums/ble_v2/BUILD
+++ b/connections/implementation/mediums/ble_v2/BUILD
@@ -80,13 +80,17 @@ cc_test(
     ],
     deps = [
         ":ble_v2",
+        "//connections/implementation/mediums:utils",
         "//internal/platform:base",
         "//internal/platform:comm",
         "//internal/platform:test_util",
         "//internal/platform:types",
+        "//internal/platform:uuid",
+        "//internal/platform/implementation:comm",
         "//internal/platform/implementation/g3",  # buildcleaner: keep
         "//proto/mediums:ble_frames_cc_proto",
         "@com_github_protobuf_matchers//protobuf-matchers",
+        "@com_google_absl//absl/base:core_headers",
         "@com_google_absl//absl/hash:hash_testing",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
diff --git a/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker.cc b/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker.cc
index 802e98c2..06b1aca4 100644
--- a/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker.cc
+++ b/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker.cc
@@ -21,6 +21,7 @@
 #include <utility>
 #include <vector>
 
+#include "absl/container/flat_hash_map.h"
 #include "absl/status/statusor.h"
 #include "absl/strings/escaping.h"
 #include "connections/implementation/flags/nearby_connections_feature_flags.h"
@@ -31,6 +32,7 @@
 #include "connections/implementation/mediums/ble_v2/bloom_filter.h"
 #include "connections/implementation/mediums/ble_v2/discovered_peripheral_callback.h"
 #include "connections/implementation/mediums/ble_v2/instant_on_lost_advertisement.h"
+#include "connections/implementation/mediums/lost_entity_tracker.h"
 #include "internal/flags/nearby_flags.h"
 #include "internal/platform/ble_v2.h"
 #include "internal/platform/byte_array.h"
@@ -39,6 +41,7 @@
 #include "internal/platform/logging.h"
 #include "internal/platform/multi_thread_executor.h"
 #include "internal/platform/mutex_lock.h"
+#include "internal/platform/uuid.h"
 
 using ::nearby::api::ble_v2::BleAdvertisementData;
 
@@ -173,18 +176,27 @@ bool DiscoveredPeripheralTracker::HandleOnLostAdvertisementLocked(
             << ": Discarding OnLost advertisement for untracked service_id";
         return false;
       }
-      auto advertisements =
+
+      auto gatt_advertisements =
           gatt_advertisements_[it.second.advertisement_header];
-      for (const auto& advertisement : advertisements) {
-        if (advertisement.IsValid()) {
+
+      // Need to report OnLost for each gatt_advertisement.
+      for (const auto& gatt_advertisement : gatt_advertisements) {
+        BleV2Peripheral lost_peripheral = it.second.peripheral;
+        lost_peripheral.SetId(ByteArray(gatt_advertisement));
+        if (gatt_advertisement.IsValid()) {
           discovery_cb_it->second.discovered_peripheral_callback
-              .peripheral_lost_cb(peripheral, it.second.service_id,
-                                  advertisement.GetData(), false);
+              .peripheral_lost_cb(lost_peripheral, it.second.service_id,
+                                  gatt_advertisement.GetData(),
+                                  gatt_advertisement.IsFastAdvertisement());
           NEARBY_LOGS(INFO) << __func__ << ": OnLost triggered for service_id "
                             << it.second.service_id;
-          return true;
         }
+
+        ClearGattAdvertisement(gatt_advertisement);
       }
+
+      return true;
     }
   }
   return false;
diff --git a/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker_test.cc b/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker_test.cc
index 65093eab..cf2a6a66 100644
--- a/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker_test.cc
+++ b/connections/implementation/mediums/ble_v2/discovered_peripheral_tracker_test.cc
@@ -16,20 +16,31 @@
 
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "gmock/gmock.h"
 #include "protobuf-matchers/protocol-buffer-matchers.h"
 #include "gtest/gtest.h"
+#include "absl/base/thread_annotations.h"
+#include "absl/strings/string_view.h"
+#include "absl/time/time.h"
 #include "connections/implementation/mediums/ble_v2/advertisement_read_result.h"
+#include "connections/implementation/mediums/ble_v2/ble_advertisement.h"
+#include "connections/implementation/mediums/ble_v2/ble_advertisement_header.h"
 #include "connections/implementation/mediums/ble_v2/ble_utils.h"
 #include "connections/implementation/mediums/ble_v2/bloom_filter.h"
 #include "connections/implementation/mediums/ble_v2/instant_on_lost_advertisement.h"
+#include "connections/implementation/mediums/utils.h"
 #include "internal/platform/ble_v2.h"
+#include "internal/platform/bluetooth_adapter.h"
+#include "internal/platform/byte_array.h"
 #include "internal/platform/count_down_latch.h"
 #include "internal/platform/feature_flags.h"
+#include "internal/platform/implementation/ble_v2.h"
 #include "internal/platform/medium_environment.h"
 #include "internal/platform/mutex.h"
 #include "internal/platform/mutex_lock.h"
+#include "internal/platform/uuid.h"
 
 namespace nearby {
 namespace connections {
@@ -74,6 +85,19 @@ ByteArray CreateLegacyBleAdvertisement(const std::string& service_id,
       data, device_token, BleAdvertisementHeader::kDefaultPsmValue));
 }
 
+BleAdvertisementHeader CreateFastBleAdvertisementHeader(
+    const ByteArray& advertisement_bytes) {
+  BloomFilter bloom_filter(
+      std::make_unique<BitSetImpl<
+          BleAdvertisementHeader::kServiceIdBloomFilterByteLength>>());
+
+  return BleAdvertisementHeader(
+      BleAdvertisementHeader::Version::kV2, /*extended_advertisement=*/false,
+      /*num_slots=*/1, ByteArray(bloom_filter),
+      bleutils::GenerateAdvertisementHash(advertisement_bytes),
+      /*psm=*/BleAdvertisementHeader::kDefaultPsmValue);
+}
+
 ByteArray CreateBleAdvertisementHeader(const ByteArray& advertisement_hash,
                                        int psm,
                                        std::vector<std::string>& service_ids) {
@@ -812,7 +836,7 @@ TEST_F(DiscoveredPeripheralTrackerTest, LostPeripheralForAdvertisementLost) {
   EXPECT_EQ(GetFetchAdvertisementCallbackCount(), 1);
 
   // Then, go through two cycles of onLost. The first cycle should include the
-  // recently discovered eripheral in its 'found' pool. The second one should
+  // recently discovered peripheral in its 'found' pool. The second one should
   // trigger the onLost callback.
   discovered_peripheral_tracker_.ProcessLostGattAdvertisements();
   discovered_peripheral_tracker_.ProcessLostGattAdvertisements();
@@ -1024,6 +1048,69 @@ TEST_F(DiscoveredPeripheralTrackerTest, LostPeripheralForInstantOnLost) {
   EXPECT_TRUE(lost_latch.Await(kWaitDuration).result());
 }
 
+TEST_F(DiscoveredPeripheralTrackerTest,
+       LostPeripheralWithFastAdvertisementForInstantOnLost) {
+  ByteArray fast_advertisement_bytes = CreateFastBleAdvertisement(
+      ByteArray(std::string(kData)), ByteArray(std::string(kDeviceToken)));
+
+  // Used to get advertisement hash from fast advertisement bytes.
+  BleAdvertisementHeader ble_advertisement_header =
+      CreateFastBleAdvertisementHeader(fast_advertisement_bytes);
+
+  ByteArray advertisement_hash =
+      ble_advertisement_header.GetAdvertisementHash();
+
+  CountDownLatch found_latch(1);
+  CountDownLatch lost_latch(1);
+  CountDownLatch fetch_latch(1);
+
+  discovered_peripheral_tracker_.StartTracking(
+      std::string(kServiceIdA),
+      {
+          .peripheral_discovered_cb =
+              [&found_latch](BleV2Peripheral peripheral,
+                             const std::string& service_id,
+                             const ByteArray& advertisement_bytes,
+                             bool fast_advertisement) {
+                EXPECT_EQ(advertisement_bytes, ByteArray(std::string(kData)));
+                EXPECT_TRUE(fast_advertisement);
+                found_latch.CountDown();
+              },
+          .peripheral_lost_cb =
+              [&lost_latch](
+                  BleV2Peripheral peripheral, const std::string& service_id,
+                  const ByteArray& advertisement_bytes,
+                  bool fast_advertisement) { lost_latch.CountDown(); },
+      },
+      Uuid(kFastAdvertisementServiceUuid));
+
+  api::ble_v2::BleAdvertisementData advertisement_data{};
+  if (!fast_advertisement_bytes.Empty()) {
+    advertisement_data.service_data.insert(
+        {Uuid(kFastAdvertisementServiceUuid), fast_advertisement_bytes});
+  }
+
+  FindFastAdvertisement(advertisement_data, {}, fetch_latch);
+
+  // We should receive a client callback of a peripheral discovery.
+  fetch_latch.Await(kWaitDuration);
+  ASSERT_TRUE(found_latch.Await(kWaitDuration).result());
+
+  auto advertisement = InstantOnLostAdvertisement::CreateFromHash(
+      advertisement_hash.AsStringView());
+  ASSERT_OK(advertisement);
+  api::ble_v2::BleAdvertisementData loss_advertisement_data{};
+  loss_advertisement_data.service_data.insert(
+      {bleutils::kCopresenceServiceUuid, ByteArray(advertisement->ToBytes())});
+
+  FindAdvertisement(loss_advertisement_data,
+                    {ByteArray(advertisement->ToBytes())}, fetch_latch);
+
+
+  // We should receive a client callback of a lost peripheral
+  EXPECT_TRUE(lost_latch.Await(kWaitDuration).result());
+}
+
 TEST_F(DiscoveredPeripheralTrackerTest, HandleDummyAdvertisement) {
   auto flag = nearby::FeatureFlags::Flags{
       .enable_invoking_legacy_device_discovered_cb = true,
diff --git a/connections/implementation/p2p_cluster_pcp_handler.cc b/connections/implementation/p2p_cluster_pcp_handler.cc
index 13f26157..270d3406 100644
--- a/connections/implementation/p2p_cluster_pcp_handler.cc
+++ b/connections/implementation/p2p_cluster_pcp_handler.cc
@@ -14,7 +14,7 @@
 
 #include "connections/implementation/p2p_cluster_pcp_handler.h"
 
-#include <algorithm>
+#include <cstddef>
 #include <memory>
 #include <string>
 #include <utility>
@@ -22,25 +22,46 @@
 
 #include "absl/functional/bind_front.h"
 #include "absl/strings/escaping.h"
+#include "absl/strings/str_format.h"
+#include "absl/strings/string_view.h"
+#include "connections/advertising_options.h"
+#include "connections/discovery_options.h"
 #include "connections/implementation/base_pcp_handler.h"
 #include "connections/implementation/ble_advertisement.h"
 #include "connections/implementation/ble_endpoint_channel.h"
 #include "connections/implementation/ble_v2_endpoint_channel.h"
+#include "connections/implementation/bluetooth_device_name.h"
 #include "connections/implementation/bluetooth_endpoint_channel.h"
 #include "connections/implementation/bwu_manager.h"
+#include "connections/implementation/client_proxy.h"
+#include "connections/implementation/endpoint_channel_manager.h"
+#include "connections/implementation/endpoint_manager.h"
 #include "connections/implementation/flags/nearby_connections_feature_flags.h"
+#include "connections/implementation/injected_bluetooth_device_store.h"
+#include "connections/implementation/mediums/mediums.h"
 #include "connections/implementation/mediums/utils.h"
+#include "connections/implementation/pcp.h"
+#include "connections/implementation/pcp_handler.h"
 #include "connections/implementation/wifi_lan_endpoint_channel.h"
+#include "connections/implementation/wifi_lan_service_info.h"
 #include "connections/medium_selector.h"
+#include "connections/out_of_band_connection_metadata.h"
 #include "connections/power_level.h"
 #include "connections/status.h"
+#include "connections/v3/connection_listening_options.h"
 #include "internal/flags/nearby_flags.h"
 #include "internal/interop/device.h"
+#include "internal/platform/ble.h"
+#include "internal/platform/ble_v2.h"
+#include "internal/platform/bluetooth_adapter.h"
+#include "internal/platform/bluetooth_classic.h"
+#include "internal/platform/byte_array.h"
 #include "internal/platform/implementation/platform.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/nsd_service_info.h"
 #include "internal/platform/os_name.h"
 #include "internal/platform/types.h"
+#include "internal/platform/wifi_lan.h"
 #include "proto/connections_enums.pb.h"
 
 namespace nearby {