We are currently facing issue that the join accept is failing when end-node is trying to send data to Tecktelic Lora gateway server. Is there any way we can subscibe the topics published by MQTT Broker on Lora gateway so that we can traceback the issue we are facing.
Or anyother way to track data recieved at UDP Packet forwarder(Semtech)
https://www.chirpstack.io/project/guides/connect-gateway/ and https://www.chirpstack.io/project/guides/connect-device/ contain different examples for debugging 
(both MQTT and UDP).
Hi
Thanks for your prompt reply. Actually i followed all the steps the links you shared. MQTT is up and running and is successfully able to communicate to Chirpstack Lora Server. But my concern is either we can trace back all the data that end device is sending to Semtec Packet forwarder or from Gateway bridge.
If we can find the topics that mqtt publish when data is made forwarded to network-server so that we can have a good know-how of the packets that are being passed to network server. And what headers other things being added to packets by gateway to pass .
That is in the Gateway Bridge configuration. Also the network server configuration.
I am totally new to this domain. Please suggest are you talking about toml files for Gw Bridge and NS. Please guide.
Sure, docs are here:
https://www.chirpstack.io/gateway-bridge/install/config/
https://www.chirpstack.io/network-server/install/config/
Search for MQTT.
I am extremely thankful for your prompt support.
@bconway @brocaar Can you help me on my another issue listed slightly_smiling_face:
I have made some progress that i am getting join request for our end node to network server but after join accept it is making error “jwt token is expired” . I am not sure how to pass jwt token in end node code.
jwt_expiration keyword in network bridge config is not helping much.