ChirpStack Gateway Showing Offline? A Step-by-Step Troubleshooting Guide

Start with the data path

A gateway that shows as offline in ChirpStack is a symptom, not a diagnosis. Traffic has to make it through several hops before ChirpStack marks a gateway as seen:

1. Gateway — running the Semtech UDP packet forwarder or LoRa Basics™ Station
2. ChirpStack Gateway Bridge — on the gateway itself or on a server
3. MQTT broker — usually Mosquitto
4. ChirpStack — subscribed to the gateway topics for its configured regions

The fastest way to fix the problem is to find the hop where traffic stops. Work through the checks below in order.

1) Does the gateway ID match exactly?

This is the most common cause by far. The gateway ID registered in ChirpStack must match the ID the gateway actually reports — character for character.

• For the UDP packet forwarder, check gateway_ID in global_conf.json or local_conf.json
• Some gateways derive the ID from the MAC address and insert FFFE or FFFF in the middle — check what the gateway really sends
• Gateway Bridge logs show the ID of every gateway it hears from; compare it with what you registered

2) Is the gateway reaching the Gateway Bridge?

Semtech UDP packet forwarder:

• Check server_address and the up/down ports (normally UDP 1700) in the gateway configuration
• Make sure UDP 1700 is open on any firewall or cloud security group in between
• Watch the Gateway Bridge logs — on systemd hosts, journalctl -u chirpstack-gateway-bridge -f — for incoming packets

LoRa Basics Station:

• Check the LNS URI (ws:// or wss://), hostname and port match the Gateway Bridge Basics Station backend
• For TLS, confirm the certificates are valid and trusted by the gateway
• Make sure the gateway's clock is correct — a wrong date breaks TLS

3) Is the Gateway Bridge publishing to the right topic?

In ChirpStack v4, gateway MQTT topics are prefixed with the region ID, for example eu868/gateway/<gateway id>/event/up. The prefix in the Gateway Bridge configuration has to match a region that is enabled in ChirpStack.

Subscribe to the broker and watch what actually arrives:

mosquitto_sub -h localhost -t '+/gateway/+/event/+' -v

If you see events for your gateway under the wrong prefix — or under no prefix at all — the Gateway Bridge configuration is the problem, not the gateway.

4) Can ChirpStack and the Gateway Bridge both log in to MQTT?

If your broker requires authentication (it should), both the Gateway Bridge and ChirpStack need valid credentials and ACLs that allow them to publish and subscribe to the gateway topics. Check the broker log for refused connections or denied subscriptions.

5) Is the region enabled in ChirpStack?

ChirpStack only subscribes to topics for the regions listed as enabled in its configuration. A gateway publishing to au915_0/... will never be seen if only eu868 is enabled. Check the ChirpStack startup log to confirm which regions it loaded.

6) Uplinks are arriving, but the gateway still looks offline

ChirpStack uses gateway status (stats) messages to decide whether a gateway is online. If the gateway forwards uplinks but its stats messages are not arriving — for example because the stats interval is disabled or very long in the packet forwarder configuration — it can appear offline even while traffic flows. Check the stats interval on the gateway and compare it with the interval configured for the gateway in ChirpStack.

7) It works for a while, then drops

Intermittent offline gateways usually point to the network rather than the configuration:

• NAT and UDP timeouts on 4G routers and firewalls can silently drop the UDP session
• Mobile backhaul with poor signal causes regular reconnects
• Broker or server restarts without proper reconnect behaviour
• Resource limits on small servers — check memory, disk space and CPU around the time of the drop

Quick checklist

Check	Where to look
Gateway ID matches	Gateway config vs ChirpStack gateway page
Packets reach Gateway Bridge	Gateway Bridge logs
Correct region topic prefix	mosquitto_sub output
MQTT credentials and ACLs	Broker logs
Region enabled	ChirpStack configuration and startup log
Stats messages arriving	Gateway config and ChirpStack gateway page
Stable backhaul	Gateway logs, router, server resources

Still offline?

If gateways are dropping across a production network, it is worth getting someone who has seen the problem before. Gateway connectivity is also only half the story — if gateways are fine but devices won't join, read why your devices won't join ChirpStack.

Production network down? Talk to a ChirpStack engineer. Our Priority Support plans include 24/7 incident response from engineers who run ChirpStack every day.