diff --git a/build.sh b/build.sh
index 0370063a..1697e0c4 100755
--- a/build.sh
+++ b/build.sh
@@ -527,7 +527,7 @@ prompt_for_radio_build_settings() {
 prompt_for_firmware_profile_settings() {
   local -a options=(
     "Keep target defaults"
-    "Cascade: path.hash.mode=2 / loop.detect=minimal / rxdelay=2 / agc.reset.interval=8 / advert.interval=0 / flood.advert.interval=83 / multi.acks=1"
+    "Cascade: path.hash.mode=2 / loop.detect=minimal / rxdelay=2 / agc.reset.interval=8 / advert.interval=0 / flood.advert.interval=83 / multi.acks=1 / companion.manual.add=1 / companion.autoadd=0"
   )
 
   clear_firmware_profile_overrides
diff --git a/docs/cli_commands.md b/docs/cli_commands.md
index 48b76245..1971709a 100644
--- a/docs/cli_commands.md
+++ b/docs/cli_commands.md
@@ -768,6 +768,74 @@ send text.flood checking ridge link
 
 ---
 
+#### Forward flood group data packets on repeaters
+**Usage:**
+- `get flood.channel.data`
+- `set flood.channel.data <on|off>`
+
+**Parameters:**
+- `on`: Retransmit received flood `GRP_DATA` channel packets.
+- `off`: Do not retransmit received flood `GRP_DATA` channel packets.
+
+**Default:** `on`
+
+**Forwarding behavior:** Repeater firmware only. The repeater still receives and
+logs the packet when logging is enabled; this only blocks retransmission.
+This is checked before `flood.channel.block` and applies to every flood
+`GRP_DATA` packet regardless of channel key. Flood group text (`GRP_TXT`) is
+unaffected.
+
+---
+
+#### Block selected flood channel packets on repeaters
+**Usage:**
+- `get flood.channel.block`
+- `get flood.channel.block.<n>`
+- `get flood.channel.block <name|8_hex_prefix>`
+- `set flood.channel.block <key> <name>`
+- `set flood.channel.block.<n> <key> <name>`
+- `set flood.channel.block #channel`
+- `set flood.channel.block.<n> #channel`
+- `del flood.channel.block.<n>`
+- `del flood.channel.block <name|8_hex_prefix>`
+
+**Parameters:**
+- `n`: Slot number from `1` to `15`.
+- `key`: 128-bit or 256-bit channel key as hex.
+- `#channel`: Public hashtag channel name; derives the 128-bit channel key from the hashtag and is stored as the row name.
+- `name`: Local label for hex-key rows. Not needed for `#channel`; any extra text after `#channel` is ignored.
+- `8_hex_prefix`: First 4 bytes of the derived channel hash, shown by single-entry `get`.
+
+**Slot behavior:** Without `.n`, `set flood.channel.block` updates an existing
+row with the same derived channel prefix or name, otherwise it uses the next
+empty slot. If all 15 slots are full, the command fails. With `.n`, the command
+writes that slot.
+
+**Forwarding behavior:** Repeater firmware only. This only affects received
+flood `GRP_TXT` and `GRP_DATA` channel packets. The repeater still receives and
+logs the packet, but it does not retransmit it when a configured block entry can
+validate/decode it. If `flood.channel.data` is `off`, all flood `GRP_DATA`
+packets are blocked before this per-channel check runs.
+
+**Matching behavior:** Each block entry stores the first 4 bytes of the derived
+channel hash for display and lookup. Current group packets carry only the first
+channel-hash byte, so that byte is used as a cheap prefilter. Only entries whose
+first hash byte matches the packet try MAC/decrypt with their stored key. If
+multiple blocked channels share the same first byte, the repeater tries each
+matching key until one validates; the packet is blocked only after a successful
+MAC/decrypt.
+
+**Examples:**
+```
+set flood.channel.block #test
+set flood.channel.block.2 9cd8fcf22a47333b591d96a2b848b73f #test
+get flood.channel.block
+get flood.channel.block #test
+del flood.channel.block.2
+```
+
+---
+
 ### ACL
 
 #### Add, update or remove permissions for a companion
diff --git a/examples/simple_repeater/MyMesh.cpp b/examples/simple_repeater/MyMesh.cpp
index 30e437b6..e3054035 100644
--- a/examples/simple_repeater/MyMesh.cpp
+++ b/examples/simple_repeater/MyMesh.cpp
@@ -82,6 +82,8 @@
 
 #define LAZY_CONTACTS_WRITE_DELAY    5000
 
+#define FLOOD_CHANNEL_BLOCK_FILE      "/flood_ch_block"
+
 #ifndef REPEATERS_CHANNEL_KEY_HEX
   #define REPEATERS_CHANNEL_KEY_HEX "89db441e2814dccf0dbd2e8cc5f501a3"
 #endif
@@ -194,6 +196,25 @@ static bool buildRepeatersChannel(mesh::GroupChannel& channel) {
   return true;
 }
 
+static File openFloodChannelBlockRead(FILESYSTEM* fs, const char* filename) {
+#if defined(RP2040_PLATFORM)
+  return fs->open(filename, "r");
+#else
+  return fs->open(filename);
+#endif
+}
+
+static File openFloodChannelBlockWrite(FILESYSTEM* fs, const char* filename) {
+#if defined(NRF52_PLATFORM) || defined(STM32_PLATFORM)
+  fs->remove(filename);
+  return fs->open(filename, FILE_O_WRITE);
+#elif defined(RP2040_PLATFORM)
+  return fs->open(filename, "w");
+#else
+  return fs->open(filename, "w", true);
+#endif
+}
+
 static uint8_t batteryPercentFromMilliVolts(uint16_t batt_mv) {
   const int min_mv = BATT_MIN_MILLIVOLTS;
   const int max_mv = BATT_MAX_MILLIVOLTS;
@@ -603,12 +624,46 @@ void MyMesh::sendFloodReply(mesh::Packet* packet, unsigned long delay_millis, ui
   }
 }
 
+bool MyMesh::floodChannelBlockMatches(const FloodChannelBlockEntry& entry, const mesh::Packet* packet) const {
+  if (!entry.active || packet == NULL || !packet->isRouteFlood()) {
+    return false;
+  }
+  uint8_t type = packet->getPayloadType();
+  if (type != PAYLOAD_TYPE_GRP_TXT && type != PAYLOAD_TYPE_GRP_DATA) {
+    return false;
+  }
+  if (packet->payload_len <= PATH_HASH_SIZE + CIPHER_MAC_SIZE || packet->payload[0] != entry.hash_prefix[0]) {
+    return false;
+  }
+
+  uint8_t data[MAX_PACKET_PAYLOAD];
+  int len = mesh::Utils::MACThenDecrypt(entry.secret, data, &packet->payload[PATH_HASH_SIZE],
+                                        packet->payload_len - PATH_HASH_SIZE);
+  return len > 0;
+}
+
+bool MyMesh::shouldBlockFloodChannelForward(const mesh::Packet* packet) const {
+  for (int i = 0; i < FLOOD_CHANNEL_BLOCK_SLOTS; i++) {
+    if (floodChannelBlockMatches(flood_channel_blocks[i], packet)) {
+      MESH_DEBUG_PRINTLN("allowPacketForward: flood.channel.block matched slot=%d name=%s",
+                         i + 1, flood_channel_blocks[i].name);
+      return true;
+    }
+  }
+  return false;
+}
+
 bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
   if (_prefs.disable_fwd) return false;
   if (packet->isRouteFlood()) {
     if (packet->getPathHashCount() >= _prefs.flood_max) return false;
     if (packet->getRouteType() == ROUTE_TYPE_FLOOD && packet->getPathHashCount() >= _prefs.flood_max_unscoped) return false;
     if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->getPathHashCount() >= _prefs.flood_max_advert) return false;
+    if (!_prefs.flood_channel_data_enabled && packet->getPayloadType() == PAYLOAD_TYPE_GRP_DATA) {
+      MESH_DEBUG_PRINTLN("allowPacketForward: flood.channel.data off, blocking GRP_DATA");
+      return false;
+    }
+    if (shouldBlockFloodChannelForward(packet)) return false;
   }
   if (packet->isRouteFlood() && recv_pkt_region == NULL) {
     MESH_DEBUG_PRINTLN("allowPacketForward: unknown transport code, or wildcard not allowed for FLOOD packet");
@@ -2066,6 +2121,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   region_load_active = false;
   memset(flood_retry_bridge_states, 0, sizeof(flood_retry_bridge_states));
   recv_pkt_region = NULL;
+  memset(flood_channel_blocks, 0, sizeof(flood_channel_blocks));
 
 #if MAX_NEIGHBOURS
   memset(neighbours, 0, sizeof(neighbours));
@@ -2115,6 +2171,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_retry_max_path = FLOOD_RETRY_ROOFTOP_MAX_PATH;
   _prefs.flood_retry_bridge_enabled = 0;
   _prefs.flood_retry_advert_enabled = FLOOD_RETRY_ADVERT_DEFAULT;
+  _prefs.flood_channel_data_enabled = 1;
   _prefs.battery_alert_enabled = 0;
   _prefs.battery_alert_low_percent = BATTERY_ALERT_LOW_PERCENT_DEFAULT;
   _prefs.battery_alert_critical_percent = BATTERY_ALERT_CRITICAL_PERCENT_DEFAULT;
@@ -2158,6 +2215,7 @@ void MyMesh::begin(FILESYSTEM *fs) {
   acl.load(_fs, self_id);
   // TODO: key_store.begin();
   region_map.load(_fs);
+  loadFloodChannelBlocks();
 
   // establish default-scope
   {
@@ -2930,6 +2988,276 @@ void MyMesh::onDefaultRegionChanged(const RegionEntry* r) {
   }
 }
 
+void MyMesh::clearFloodChannelBlockEntry(FloodChannelBlockEntry& entry) {
+  memset(&entry, 0, sizeof(entry));
+}
+
+void MyMesh::deriveFloodChannelBlockPrefix(const uint8_t* secret, uint8_t key_len,
+                                           uint8_t prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN]) const {
+  mesh::Utils::sha256(prefix, FLOOD_CHANNEL_BLOCK_PREFIX_LEN, secret, key_len);
+}
+
+void MyMesh::loadFloodChannelBlocks() {
+  memset(flood_channel_blocks, 0, sizeof(flood_channel_blocks));
+  if (_fs == NULL || !_fs->exists(FLOOD_CHANNEL_BLOCK_FILE)) {
+    return;
+  }
+
+  File file = openFloodChannelBlockRead(_fs, FLOOD_CHANNEL_BLOCK_FILE);
+  if (!file) {
+    return;
+  }
+
+  uint8_t magic[4];
+  uint8_t count = 0;
+  bool success = file.read(magic, sizeof(magic)) == sizeof(magic)
+      && memcmp(magic, "FCB1", sizeof(magic)) == 0
+      && file.read(&count, sizeof(count)) == sizeof(count);
+
+  for (int i = 0; success && i < count && i < FLOOD_CHANNEL_BLOCK_SLOTS; i++) {
+    uint8_t active = 0;
+    uint8_t key_len = 0;
+    uint8_t hash_prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN];
+    uint8_t secret[PUB_KEY_SIZE];
+    char name[FLOOD_CHANNEL_BLOCK_NAME_LEN];
+
+    success = file.read(&active, sizeof(active)) == sizeof(active);
+    success = success && file.read(&key_len, sizeof(key_len)) == sizeof(key_len);
+    success = success && file.read(hash_prefix, sizeof(hash_prefix)) == sizeof(hash_prefix);
+    success = success && file.read(secret, sizeof(secret)) == sizeof(secret);
+    success = success && file.read((uint8_t*)name, sizeof(name)) == sizeof(name);
+    if (!success) {
+      break;
+    }
+
+    name[sizeof(name) - 1] = 0;
+    if (active && (key_len == CIPHER_KEY_SIZE || key_len == PUB_KEY_SIZE) && name[0] != 0) {
+      auto& entry = flood_channel_blocks[i];
+      entry.active = true;
+      entry.key_len = key_len;
+      memcpy(entry.secret, secret, sizeof(entry.secret));
+      if (entry.key_len == CIPHER_KEY_SIZE) {
+        memset(&entry.secret[CIPHER_KEY_SIZE], 0, PUB_KEY_SIZE - CIPHER_KEY_SIZE);
+      }
+      deriveFloodChannelBlockPrefix(entry.secret, entry.key_len, entry.hash_prefix);
+      StrHelper::strncpy(entry.name, name, sizeof(entry.name));
+    }
+  }
+
+  file.close();
+}
+
+bool MyMesh::saveFloodChannelBlocks() {
+  if (_fs == NULL) {
+    return false;
+  }
+
+  File file = openFloodChannelBlockWrite(_fs, FLOOD_CHANNEL_BLOCK_FILE);
+  if (!file) {
+    return false;
+  }
+
+  const uint8_t magic[4] = {'F', 'C', 'B', '1'};
+  uint8_t count = FLOOD_CHANNEL_BLOCK_SLOTS;
+  bool success = file.write(magic, sizeof(magic)) == sizeof(magic);
+  success = success && file.write(&count, sizeof(count)) == sizeof(count);
+
+  for (int i = 0; success && i < FLOOD_CHANNEL_BLOCK_SLOTS; i++) {
+    const auto& entry = flood_channel_blocks[i];
+    uint8_t active = entry.active ? 1 : 0;
+    success = file.write(&active, sizeof(active)) == sizeof(active);
+    success = success && file.write(&entry.key_len, sizeof(entry.key_len)) == sizeof(entry.key_len);
+    success = success && file.write(entry.hash_prefix, sizeof(entry.hash_prefix)) == sizeof(entry.hash_prefix);
+    success = success && file.write(entry.secret, sizeof(entry.secret)) == sizeof(entry.secret);
+    success = success && file.write((const uint8_t*)entry.name, sizeof(entry.name)) == sizeof(entry.name);
+  }
+
+  file.close();
+  return success;
+}
+
+static void trimFloodChannelBlockSelector(const char* selector, char* dest, size_t dest_len) {
+  selector = skipLocalSpaces(selector);
+  StrHelper::strncpy(dest, selector == NULL ? "" : selector, dest_len);
+  size_t len = strlen(dest);
+  while (len > 0 && dest[len - 1] == ' ') {
+    dest[--len] = 0;
+  }
+}
+
+static bool parseFloodChannelBlockPrefixSelector(const char* selector,
+                                                 uint8_t prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN]) {
+  char text[16];
+  trimFloodChannelBlockSelector(selector, text, sizeof(text));
+  if (strlen(text) != FLOOD_CHANNEL_BLOCK_PREFIX_LEN * 2) {
+    return false;
+  }
+  for (int i = 0; i < FLOOD_CHANNEL_BLOCK_PREFIX_LEN * 2; i++) {
+    if (!mesh::Utils::isHexChar(text[i])) {
+      return false;
+    }
+  }
+  return mesh::Utils::fromHex(prefix, FLOOD_CHANNEL_BLOCK_PREFIX_LEN, text);
+}
+
+int MyMesh::findFloodChannelBlockBySelector(const char* selector) const {
+  uint8_t prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN];
+  if (parseFloodChannelBlockPrefixSelector(selector, prefix)) {
+    for (int i = 0; i < FLOOD_CHANNEL_BLOCK_SLOTS; i++) {
+      const auto& entry = flood_channel_blocks[i];
+      if (entry.active && memcmp(entry.hash_prefix, prefix, sizeof(entry.hash_prefix)) == 0) {
+        return i;
+      }
+    }
+    return -1;
+  }
+
+  int index = 0;
+  if (parsePositiveSelector(selector, index)) {
+    return (index >= 1 && index <= FLOOD_CHANNEL_BLOCK_SLOTS) ? index - 1 : -1;
+  }
+
+  char name[FLOOD_CHANNEL_BLOCK_NAME_LEN];
+  trimFloodChannelBlockSelector(selector, name, sizeof(name));
+  if (name[0] == 0) {
+    return -1;
+  }
+  for (int i = 0; i < FLOOD_CHANNEL_BLOCK_SLOTS; i++) {
+    const auto& entry = flood_channel_blocks[i];
+    if (entry.active && strcmp(entry.name, name) == 0) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+int MyMesh::findFloodChannelBlockSlot(const uint8_t prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN], const char* name) const {
+  int free_slot = -1;
+  for (int i = 0; i < FLOOD_CHANNEL_BLOCK_SLOTS; i++) {
+    const auto& entry = flood_channel_blocks[i];
+    if (entry.active) {
+      if (memcmp(entry.hash_prefix, prefix, FLOOD_CHANNEL_BLOCK_PREFIX_LEN) == 0 || strcmp(entry.name, name) == 0) {
+        return i;
+      }
+    } else if (free_slot < 0) {
+      free_slot = i;
+    }
+  }
+  return free_slot;
+}
+
+void MyMesh::formatFloodChannelBlockDetail(char* reply, int idx) const {
+  if (idx < 0 || idx >= FLOOD_CHANNEL_BLOCK_SLOTS) {
+    strcpy(reply, "Err - not found");
+    return;
+  }
+
+  const auto& entry = flood_channel_blocks[idx];
+  if (!entry.active) {
+    snprintf(reply, 160, "> %d empty", idx + 1);
+    return;
+  }
+
+  char prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN * 2 + 1];
+  mesh::Utils::toHex(prefix, entry.hash_prefix, FLOOD_CHANNEL_BLOCK_PREFIX_LEN);
+  snprintf(reply, 160, "> %d %s %u %s", idx + 1, prefix, (unsigned int)entry.key_len * 8, entry.name);
+}
+
+void MyMesh::setFloodChannelBlock(int index, const uint8_t* secret, uint8_t key_len,
+                                  const char* name, char* reply) {
+  if ((key_len != CIPHER_KEY_SIZE && key_len != PUB_KEY_SIZE) || secret == NULL || name == NULL || name[0] == 0) {
+    strcpy(reply, "Err - bad params");
+    return;
+  }
+  if (index < 0 || index > FLOOD_CHANNEL_BLOCK_SLOTS) {
+    snprintf(reply, 160, "Err - index 1-%d", FLOOD_CHANNEL_BLOCK_SLOTS);
+    return;
+  }
+
+  uint8_t prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN];
+  deriveFloodChannelBlockPrefix(secret, key_len, prefix);
+  int slot = index > 0 ? index - 1 : findFloodChannelBlockSlot(prefix, name);
+  if (slot < 0 || slot >= FLOOD_CHANNEL_BLOCK_SLOTS) {
+    strcpy(reply, "Err - block list full");
+    return;
+  }
+
+  auto& entry = flood_channel_blocks[slot];
+  clearFloodChannelBlockEntry(entry);
+  entry.active = true;
+  entry.key_len = key_len;
+  memcpy(entry.secret, secret, PUB_KEY_SIZE);
+  if (entry.key_len == CIPHER_KEY_SIZE) {
+    memset(&entry.secret[CIPHER_KEY_SIZE], 0, PUB_KEY_SIZE - CIPHER_KEY_SIZE);
+  }
+  deriveFloodChannelBlockPrefix(entry.secret, entry.key_len, entry.hash_prefix);
+  StrHelper::strncpy(entry.name, name, sizeof(entry.name));
+
+  if (!saveFloodChannelBlocks()) {
+    strcpy(reply, "Err - save failed");
+    return;
+  }
+  formatFloodChannelBlockDetail(reply, slot);
+}
+
+void MyMesh::formatFloodChannelBlocks(const char* selector, char* reply) {
+  if (!selectorIsEmpty(selector)) {
+    int idx = findFloodChannelBlockBySelector(selector);
+    if (idx < 0) {
+      strcpy(reply, "Err - not found");
+    } else {
+      formatFloodChannelBlockDetail(reply, idx);
+    }
+    return;
+  }
+
+  char* out = reply;
+  size_t remaining = 160;
+  int written = snprintf(out, remaining, ">");
+  if (written < 0 || (size_t)written >= remaining) {
+    reply[0] = 0;
+    return;
+  }
+  out += written;
+  remaining -= written;
+
+  for (int i = 0; i < FLOOD_CHANNEL_BLOCK_SLOTS && remaining > 1; i++) {
+    char display[8];
+    const auto& entry = flood_channel_blocks[i];
+    if (!entry.active) {
+      strcpy(display, "-");
+    } else {
+      StrHelper::strncpy(display, entry.name, sizeof(display));
+      if (strlen(entry.name) >= sizeof(display)) {
+        display[sizeof(display) - 2] = '~';
+        display[sizeof(display) - 1] = 0;
+      }
+    }
+    written = snprintf(out, remaining, " %d:%s", i + 1, display);
+    if (written < 0 || (size_t)written >= remaining) {
+      out[remaining - 1] = 0;
+      break;
+    }
+    out += written;
+    remaining -= written;
+  }
+}
+
+void MyMesh::deleteFloodChannelBlock(const char* selector, char* reply) {
+  int idx = findFloodChannelBlockBySelector(selector);
+  if (idx < 0 || idx >= FLOOD_CHANNEL_BLOCK_SLOTS || !flood_channel_blocks[idx].active) {
+    strcpy(reply, "Err - not found");
+    return;
+  }
+
+  clearFloodChannelBlockEntry(flood_channel_blocks[idx]);
+  if (!saveFloodChannelBlocks()) {
+    strcpy(reply, "Err - save failed");
+    return;
+  }
+  strcpy(reply, "OK");
+}
+
 void MyMesh::formatStatsReply(char *reply) {
   StatsFormatHelper::formatCoreStats(reply, board, *_ms, _err_flags, _mgr);
 }
diff --git a/examples/simple_repeater/MyMesh.h b/examples/simple_repeater/MyMesh.h
index c521c80c..83485b25 100644
--- a/examples/simple_repeater/MyMesh.h
+++ b/examples/simple_repeater/MyMesh.h
@@ -132,7 +132,15 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
     uint8_t progress_marker;
     bool active;
   };
+  struct FloodChannelBlockEntry {
+    bool active;
+    uint8_t key_len;
+    uint8_t hash_prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN];
+    uint8_t secret[PUB_KEY_SIZE];
+    char name[FLOOD_CHANNEL_BLOCK_NAME_LEN];
+  };
   mutable FloodRetryBridgeState flood_retry_bridge_states[MAX_FLOOD_RETRY_SLOTS];
+  FloodChannelBlockEntry flood_channel_blocks[FLOOD_CHANNEL_BLOCK_SLOTS];
   uint32_t pending_discover_tag;
   unsigned long pending_discover_until;
   bool region_load_active;
@@ -193,6 +201,16 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
   void applySavedRadioParams();
   void processScheduledRadioSettings();
   bool isMillisTimerDue(unsigned long timestamp) const;
+  void loadFloodChannelBlocks();
+  bool saveFloodChannelBlocks();
+  void clearFloodChannelBlockEntry(FloodChannelBlockEntry& entry);
+  void deriveFloodChannelBlockPrefix(const uint8_t* secret, uint8_t key_len,
+                                     uint8_t prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN]) const;
+  bool floodChannelBlockMatches(const FloodChannelBlockEntry& entry, const mesh::Packet* packet) const;
+  bool shouldBlockFloodChannelForward(const mesh::Packet* packet) const;
+  int findFloodChannelBlockBySelector(const char* selector) const;
+  int findFloodChannelBlockSlot(const uint8_t prefix[FLOOD_CHANNEL_BLOCK_PREFIX_LEN], const char* name) const;
+  void formatFloodChannelBlockDetail(char* reply, int idx) const;
   bool hasScheduledRadioWorkDue() const;
   uint32_t limitSleepToMillisTimer(unsigned long timestamp, uint32_t sleep_secs) const;
   uint32_t limitSleepToRtcTime(uint32_t timestamp, uint32_t sleep_secs) const;
@@ -323,6 +341,10 @@ public:
   void startRegionsLoad() override;
   bool saveRegions() override;
   void onDefaultRegionChanged(const RegionEntry* r) override;
+  void setFloodChannelBlock(int index, const uint8_t* secret, uint8_t key_len,
+                            const char* name, char* reply) override;
+  void formatFloodChannelBlocks(const char* selector, char* reply) override;
+  void deleteFloodChannelBlock(const char* selector, char* reply) override;
 
   mesh::LocalIdentity& getSelfId() override { return self_id; }
 
diff --git a/examples/simple_room_server/MyMesh.cpp b/examples/simple_room_server/MyMesh.cpp
index dbb7eefa..b97228f3 100644
--- a/examples/simple_room_server/MyMesh.cpp
+++ b/examples/simple_room_server/MyMesh.cpp
@@ -648,6 +648,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_max = 64;
   _prefs.flood_max_unscoped = 64;
   _prefs.flood_max_advert = 8;
+  _prefs.flood_channel_data_enabled = 1;
   _prefs.interference_threshold = 0; // disabled
   _prefs.cad_enabled = 0;            // hardware CAD before TX (off by default; 'set cad on')
 #ifdef ROOM_PASSWORD
diff --git a/examples/simple_sensor/SensorMesh.cpp b/examples/simple_sensor/SensorMesh.cpp
index 59c9aa09..99e10bc8 100644
--- a/examples/simple_sensor/SensorMesh.cpp
+++ b/examples/simple_sensor/SensorMesh.cpp
@@ -728,6 +728,7 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.flood_advert_interval = 0;   // disabled
   _prefs.disable_fwd = true;
   _prefs.flood_max = 64;
+  _prefs.flood_channel_data_enabled = 1;
   _prefs.interference_threshold = 0;  // disabled
   _prefs.cad_enabled = 0;             // hardware CAD before TX (off by default; 'set cad on')
 
diff --git a/src/helpers/CommonCLI.cpp b/src/helpers/CommonCLI.cpp
index 9c312deb..c43b2948 100644
--- a/src/helpers/CommonCLI.cpp
+++ b/src/helpers/CommonCLI.cpp
@@ -380,6 +380,69 @@ static bool parseFloodRetryPrefixList(uint8_t dest[][FLOOD_RETRY_PREFIX_LEN], ui
   return true;
 }
 
+static bool parseFloodChannelBlockKey(const char* text, uint8_t secret[PUB_KEY_SIZE], uint8_t& key_len) {
+  if (text == NULL || text[0] == 0) {
+    return false;
+  }
+
+  memset(secret, 0, PUB_KEY_SIZE);
+  if (text[0] == '#') {
+    if (!isValidName(text)) {
+      return false;
+    }
+    mesh::Utils::sha256(secret, CIPHER_KEY_SIZE, (const uint8_t*)text, strlen(text));
+    key_len = CIPHER_KEY_SIZE;
+    return true;
+  }
+
+  size_t hex_len = strlen(text);
+  if (!(hex_len == CIPHER_KEY_SIZE * 2 || hex_len == PUB_KEY_SIZE * 2)) {
+    return false;
+  }
+  for (size_t i = 0; i < hex_len; i++) {
+    if (!mesh::Utils::isHexChar(text[i])) {
+      return false;
+    }
+  }
+
+  key_len = (uint8_t)(hex_len / 2);
+  return mesh::Utils::fromHex(secret, key_len, text);
+}
+
+static bool parseFloodChannelBlockDotIndex(const char*& cursor, int& index) {
+  if (*cursor != '.') {
+    index = 0;
+    return true;
+  }
+
+  cursor++;
+  if (*cursor < '0' || *cursor > '9') {
+    return false;
+  }
+  int value = 0;
+  while (*cursor >= '0' && *cursor <= '9') {
+    value = (value * 10) + (*cursor - '0');
+    if (value > FLOOD_CHANNEL_BLOCK_SLOTS) {
+      return false;
+    }
+    cursor++;
+  }
+  if (value < 1) {
+    return false;
+  }
+  index = value;
+  return true;
+}
+
+static void copyTrimmedFloodChannelBlockName(char* dest, size_t dest_len, const char* src) {
+  src = skipSpacesConst(src);
+  StrHelper::strncpy(dest, src, dest_len);
+  size_t len = strlen(dest);
+  while (len > 0 && dest[len - 1] == ' ') {
+    dest[--len] = 0;
+  }
+}
+
 static void applyDirectRetryPreset(NodePrefs* prefs, uint8_t preset) {
   prefs->retry_preset = preset;
   if (preset == RETRY_PRESET_INFRA) {
@@ -547,6 +610,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     _prefs->battery_alert_low_percent = BATTERY_ALERT_LOW_PERCENT_DEFAULT;
     _prefs->battery_alert_critical_percent = BATTERY_ALERT_CRITICAL_PERCENT_DEFAULT;
     _prefs->direct_retry_recent_enabled = DIRECT_RETRY_RECENT_DEFAULT;
+    _prefs->flood_channel_data_enabled = 1;
     bool has_flood_retry_prefs = file.available() >= 2;
     if (has_flood_retry_prefs) {
       file.read((uint8_t *)&_prefs->flood_retry_attempts, sizeof(_prefs->flood_retry_attempts));     // 311
@@ -578,8 +642,11 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
       if (file.available() >= (int)sizeof(_prefs->direct_retry_recent_enabled)) {
         file.read((uint8_t *)&_prefs->direct_retry_recent_enabled, sizeof(_prefs->direct_retry_recent_enabled));
       }
+      if (file.available() >= (int)sizeof(_prefs->flood_channel_data_enabled)) {
+        file.read((uint8_t *)&_prefs->flood_channel_data_enabled, sizeof(_prefs->flood_channel_data_enabled));
+      }
     }
-    // next: 672
+    // next: 673
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -639,6 +706,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     _prefs->flood_retry_advert_enabled = constrain(_prefs->flood_retry_advert_enabled, 0, 1);
     _prefs->battery_alert_enabled = constrain(_prefs->battery_alert_enabled, 0, 1);
     _prefs->direct_retry_recent_enabled = constrain(_prefs->direct_retry_recent_enabled, 0, 1);
+    _prefs->flood_channel_data_enabled = constrain(_prefs->flood_channel_data_enabled, 0, 1);
     if (_prefs->battery_alert_low_percent < 1
         || _prefs->battery_alert_low_percent > 100
         || _prefs->battery_alert_critical_percent >= _prefs->battery_alert_low_percent) {
@@ -736,7 +804,8 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->battery_alert_low_percent, sizeof(_prefs->battery_alert_low_percent));
     file.write((uint8_t *)&_prefs->battery_alert_critical_percent, sizeof(_prefs->battery_alert_critical_percent));
     file.write((uint8_t *)&_prefs->direct_retry_recent_enabled, sizeof(_prefs->direct_retry_recent_enabled));
-    // next: 672
+    file.write((uint8_t *)&_prefs->flood_channel_data_enabled, sizeof(_prefs->flood_channel_data_enabled));
+    // next: 673
 
     file.close();
   }
@@ -1380,6 +1449,54 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
     } else {
       strcpy(reply, "Error, must be 0-5000 ms");
     }
+  } else if (memcmp(config, "flood.channel.data ", 19) == 0) {
+    if (strcmp(&config[19], "on") == 0) {
+      _prefs->flood_channel_data_enabled = 1;
+      savePrefs();
+      strcpy(reply, "OK");
+    } else if (strcmp(&config[19], "off") == 0) {
+      _prefs->flood_channel_data_enabled = 0;
+      savePrefs();
+      strcpy(reply, "OK");
+    } else {
+      strcpy(reply, "Error, must be on or off");
+    }
+  } else if (memcmp(config, "flood.channel.block", 19) == 0
+      && (config[19] == ' ' || config[19] == '.')) {
+    const char* cursor = &config[19];
+    int index = 0;
+    if (!parseFloodChannelBlockDotIndex(cursor, index)) {
+      sprintf(reply, "Error, index 1-%d", FLOOD_CHANNEL_BLOCK_SLOTS);
+      return;
+    }
+    cursor = skipSpacesConst(cursor);
+
+    const char* key_start = cursor;
+    while (*cursor && *cursor != ' ') cursor++;
+    size_t key_len_text = cursor - key_start;
+    char key_text[PUB_KEY_SIZE * 2 + 1];
+    if (key_len_text == 0 || key_len_text >= sizeof(key_text)) {
+      strcpy(reply, "Error, use: set flood.channel.block[.n] <hex-key> <name>|#channel");
+      return;
+    }
+    memcpy(key_text, key_start, key_len_text);
+    key_text[key_len_text] = 0;
+
+    char name[FLOOD_CHANNEL_BLOCK_NAME_LEN];
+    if (key_text[0] == '#') {
+      StrHelper::strncpy(name, key_text, sizeof(name));
+    } else {
+      copyTrimmedFloodChannelBlockName(name, sizeof(name), cursor);
+    }
+    uint8_t secret[PUB_KEY_SIZE];
+    uint8_t decoded_key_len = 0;
+    if (!parseFloodChannelBlockKey(key_text, secret, decoded_key_len)) {
+      strcpy(reply, "Error, key must be 128/256-bit hex or #channel");
+    } else if (name[0] == 0 || !isValidName(name)) {
+      strcpy(reply, "Error, bad name");
+    } else {
+      _callbacks->setFloodChannelBlock(index, secret, decoded_key_len, name, reply);
+    }
   } else if (memcmp(config, "flood.retry.count ", 18) == 0) {
     int attempts = looksUnsignedInteger(&config[18]) ? _atoi(&config[18]) : -1;
     if (attempts >= 0 && attempts <= 15) {
@@ -1702,6 +1819,28 @@ void CommonCLI::handleGetCmd(uint32_t sender_timestamp, char* command, char* rep
     sprintf(reply, "> %s", StrHelper::ftoa(_prefs->rx_delay_base));
   } else if (memcmp(config, "txdelay", 7) == 0) {
     sprintf(reply, "> %s", StrHelper::ftoa(_prefs->tx_delay_factor));
+  } else if (memcmp(config, "flood.channel.data", 18) == 0) {
+    sprintf(reply, "> %s", _prefs->flood_channel_data_enabled ? "on" : "off");
+  } else if (memcmp(config, "flood.channel.block", 19) == 0
+      && (config[19] == 0 || config[19] == ' ' || config[19] == '.')) {
+    const char* cursor = &config[19];
+    int index = 0;
+    if (!parseFloodChannelBlockDotIndex(cursor, index)) {
+      sprintf(reply, "Error, index 1-%d", FLOOD_CHANNEL_BLOCK_SLOTS);
+      return;
+    }
+    cursor = skipSpacesConst(cursor);
+    char selector[8];
+    if (index > 0 && *cursor != 0) {
+      strcpy(reply, "Error, use index or selector");
+      return;
+    }
+    if (index > 0) {
+      snprintf(selector, sizeof(selector), "%d", index);
+      _callbacks->formatFloodChannelBlocks(selector, reply);
+    } else {
+      _callbacks->formatFloodChannelBlocks(cursor, reply);
+    }
   } else if (memcmp(config, "flood.max.advert", 16) == 0) {
     sprintf(reply, "> %d", (uint32_t)_prefs->flood_max_advert);
   } else if (memcmp(config, "flood.max.unscoped", 18) == 0) {
@@ -1880,6 +2019,28 @@ void CommonCLI::handleDelCmd(char* command, char* reply) {
     _callbacks->deleteScheduledRadioParams(true, skipSpacesConst(&config[11]), reply);
   } else if (memcmp(config, "radioat", 7) == 0 && (config[7] == 0 || config[7] == ' ')) {
     _callbacks->deleteScheduledRadioParams(false, skipSpacesConst(&config[7]), reply);
+  } else if (memcmp(config, "flood.channel.block", 19) == 0
+      && (config[19] == ' ' || config[19] == '.')) {
+    const char* cursor = &config[19];
+    int index = 0;
+    if (!parseFloodChannelBlockDotIndex(cursor, index)) {
+      sprintf(reply, "Error, index 1-%d", FLOOD_CHANNEL_BLOCK_SLOTS);
+      return;
+    }
+    cursor = skipSpacesConst(cursor);
+    char selector[8];
+    if (index > 0 && *cursor != 0) {
+      strcpy(reply, "Error, use index or selector");
+      return;
+    }
+    if (index > 0) {
+      snprintf(selector, sizeof(selector), "%d", index);
+      _callbacks->deleteFloodChannelBlock(selector, reply);
+    } else if (*cursor != 0) {
+      _callbacks->deleteFloodChannelBlock(cursor, reply);
+    } else {
+      strcpy(reply, "Error, use: del flood.channel.block <index|name|prefix>");
+    }
   } else {
     strcpy(reply, "unknown del: ");
     StrHelper::strncpy(&reply[13], config, 160 - 14);
diff --git a/src/helpers/CommonCLI.h b/src/helpers/CommonCLI.h
index 38019a8f..7cfef4d4 100644
--- a/src/helpers/CommonCLI.h
+++ b/src/helpers/CommonCLI.h
@@ -78,6 +78,16 @@
   #define COMMON_CLI_TMP_LEN              ((FLOOD_RETRY_LIST_TEXT_MAX > (PRV_KEY_SIZE * 2 + 4)) ? FLOOD_RETRY_LIST_TEXT_MAX : (PRV_KEY_SIZE * 2 + 4))
 #endif
 
+#ifndef FLOOD_CHANNEL_BLOCK_SLOTS
+  #define FLOOD_CHANNEL_BLOCK_SLOTS       15
+#endif
+#ifndef FLOOD_CHANNEL_BLOCK_NAME_LEN
+  #define FLOOD_CHANNEL_BLOCK_NAME_LEN    32
+#endif
+#ifndef FLOOD_CHANNEL_BLOCK_PREFIX_LEN
+  #define FLOOD_CHANNEL_BLOCK_PREFIX_LEN  4
+#endif
+
 #define DIRECT_RETRY_CR4_MIN_SNR_X4_DEFAULT  40
 #define DIRECT_RETRY_CR5_MIN_SNR_X4_DEFAULT  30
 #define DIRECT_RETRY_CR7_MIN_SNR_X4_DEFAULT  10
@@ -156,6 +166,7 @@ struct NodePrefs { // persisted to file
   uint8_t battery_alert_low_percent;
   uint8_t battery_alert_critical_percent;
   uint8_t direct_retry_recent_enabled;
+  uint8_t flood_channel_data_enabled;
 };
 
 class CommonCLICallbacks {
@@ -216,6 +227,22 @@ public:
     (void)selector;
     strcpy(reply, "Error: unsupported");
   }
+  virtual void setFloodChannelBlock(int index, const uint8_t* secret, uint8_t key_len,
+                                    const char* name, char* reply) {
+    (void)index;
+    (void)secret;
+    (void)key_len;
+    (void)name;
+    strcpy(reply, "Error: unsupported");
+  }
+  virtual void formatFloodChannelBlocks(const char* selector, char* reply) {
+    (void)selector;
+    strcpy(reply, "Error: unsupported");
+  }
+  virtual void deleteFloodChannelBlock(const char* selector, char* reply) {
+    (void)selector;
+    strcpy(reply, "Error: unsupported");
+  }
 
   virtual void startRegionsLoad() {
     // no op by default