diff --git a/src/mesh/FloodingRouter.cpp b/src/mesh/FloodingRouter.cpp
index 142ada806..dbd458b61 100644
--- a/src/mesh/FloodingRouter.cpp
+++ b/src/mesh/FloodingRouter.cpp
@@ -47,8 +47,10 @@ void FloodingRouter::perhapsCancelDupe(const meshtastic_MeshPacket *p)
 {
     if (config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER &&
         config.device.role != meshtastic_Config_DeviceConfig_Role_REPEATER &&
-        config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER_LATE) {
+        config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER_LATE &&
+        p->transport_mechanism == meshtastic_MeshPacket_TransportMechanism_TRANSPORT_LORA) {
         // cancel rebroadcast of this message *if* there was already one, unless we're a router/repeater!
+        // But only LoRa packets should be able to trigger this.
         if (Router::cancelSending(p->from, p->id))
             txRelayCanceled++;
     }
diff --git a/src/mesh/RadioInterface.cpp b/src/mesh/RadioInterface.cpp
index 7590ac34d..99e99922b 100644
--- a/src/mesh/RadioInterface.cpp
+++ b/src/mesh/RadioInterface.cpp
@@ -170,11 +170,10 @@ const RegionInfo regions[] = {
     */
     RDEF(KZ_433, 433.075f, 434.775f, 100, 0, 10, true, false, false), RDEF(KZ_863, 863.0f, 868.0f, 100, 0, 30, true, false, true),
 
-
     /*
         Nepal
-        865 MHz to 868 MHz frequency band for IoT (Internet of Things), M2M (Machine-to-Machine), and smart metering use, specifically in non-cellular mode.
-        https://www.nta.gov.np/uploads/contents/Radio-Frequency-Policy-2080-English.pdf
+        865 MHz to 868 MHz frequency band for IoT (Internet of Things), M2M (Machine-to-Machine), and smart metering use,
+       specifically in non-cellular mode. https://www.nta.gov.np/uploads/contents/Radio-Frequency-Policy-2080-English.pdf
     */
     RDEF(NP_865, 865.0f, 868.0f, 100, 0, 30, true, false, false),
 
@@ -336,8 +335,9 @@ uint32_t RadioInterface::getTxDelayMsecWeighted(float snr)
 void printPacket(const char *prefix, const meshtastic_MeshPacket *p)
 {
 #if defined(DEBUG_PORT) && !defined(DEBUG_MUTE)
-    std::string out = DEBUG_PORT.mt_sprintf("%s (id=0x%08x fr=0x%08x to=0x%08x, WantAck=%d, HopLim=%d Ch=0x%x", prefix, p->id,
-                                            p->from, p->to, p->want_ack, p->hop_limit, p->channel);
+    std::string out =
+        DEBUG_PORT.mt_sprintf("%s (id=0x%08x fr=0x%08x to=0x%08x, transport = %u, WantAck=%d, HopLim=%d Ch=0x%x", prefix, p->id,
+                              p->from, p->to, p->transport_mechanism, p->want_ack, p->hop_limit, p->channel);
     if (p->which_payload_variant == meshtastic_MeshPacket_decoded_tag) {
         auto &s = p->decoded;
 
diff --git a/src/mesh/Router.cpp b/src/mesh/Router.cpp
index 48205cc0f..e090bd539 100644
--- a/src/mesh/Router.cpp
+++ b/src/mesh/Router.cpp
@@ -66,6 +66,7 @@ int32_t Router::runOnce()
 {
     meshtastic_MeshPacket *mp;
     while ((mp = fromRadioQueue.dequeuePtr(0)) != NULL) {
+        mp->transport_mechanism = meshtastic_MeshPacket_TransportMechanism_TRANSPORT_LORA;
         // printPacket("handle fromRadioQ", mp);
         perhapsHandleReceived(mp);
     }
diff --git a/src/mesh/api/PacketAPI.cpp b/src/mesh/api/PacketAPI.cpp
index 1d6df855f..ab380d696 100644
--- a/src/mesh/api/PacketAPI.cpp
+++ b/src/mesh/api/PacketAPI.cpp
@@ -59,6 +59,7 @@ bool PacketAPI::receivePacket(void)
         switch (mr->which_payload_variant) {
         case meshtastic_ToRadio_packet_tag: {
             meshtastic_MeshPacket *mp = &mr->packet;
+            mp->transport_mechanism = meshtastic_MeshPacket_TransportMechanism_TRANSPORT_API;
             printPacket("PACKET FROM QUEUE", mp);
             service->handleToRadio(*mp);
             break;
diff --git a/src/mesh/udp/UdpMulticastHandler.h b/src/mesh/udp/UdpMulticastHandler.h
index d4e0eaa8c..9650668a8 100644
--- a/src/mesh/udp/UdpMulticastHandler.h
+++ b/src/mesh/udp/UdpMulticastHandler.h
@@ -50,6 +50,7 @@ class UdpMulticastHandler final
         LOG_DEBUG("UDP broadcast from: %s, len=%u", packet.remoteIP().toString().c_str(), packetLength);
 #endif
         meshtastic_MeshPacket mp;
+        mp.transport_mechanism = meshtastic_MeshPacket_TransportMechanism_TRANSPORT_MULTICAST_UDP;
         LOG_DEBUG("Decoding MeshPacket from UDP len=%u", packetLength);
         bool isPacketDecoded = pb_decode_from_bytes(packet.data(), packetLength, &meshtastic_MeshPacket_msg, &mp);
         if (isPacketDecoded && router && mp.which_payload_variant == meshtastic_MeshPacket_encrypted_tag) {
@@ -78,6 +79,9 @@ class UdpMulticastHandler final
             return false;
         }
 #endif
+        if (mp->transport_mechanism == meshtastic_MeshPacket_TransportMechanism_TRANSPORT_MULTICAST_UDP) {
+            LOG_ERROR("Attempt to send UDP sourced packet over UDP");
+        }
         LOG_DEBUG("Broadcasting packet over UDP (id=%u)", mp->id);
         uint8_t buffer[meshtastic_MeshPacket_size];
         size_t encodedLength = pb_encode_to_bytes(buffer, sizeof(buffer), &meshtastic_MeshPacket_msg, mp);
diff --git a/src/mqtt/MQTT.cpp b/src/mqtt/MQTT.cpp
index 21d4a8fa0..d94aeff95 100644
--- a/src/mqtt/MQTT.cpp
+++ b/src/mqtt/MQTT.cpp
@@ -95,6 +95,7 @@ inline void onReceiveProto(char *topic, byte *payload, size_t length)
     p->hop_start = e.packet->hop_start;
     p->want_ack = e.packet->want_ack;
     p->via_mqtt = true; // Mark that the packet was received via MQTT
+    p->transport_mechanism = meshtastic_MeshPacket_TransportMechanism_TRANSPORT_MQTT;
     p->which_payload_variant = e.packet->which_payload_variant;
     memcpy(&p->decoded, &e.packet->decoded, std::max(sizeof(p->decoded), sizeof(p->encrypted)));