Node-red - can't connect MQTT

Hi everyone,
I want to test the connection between the emonPi and Node-red but the MQTT input nodes can’t connect. I see in Emonhub that values are published. I also have a connection failed with the broker:
24 Sep 10:02:22 - [info] [mqtt-broker:396670b0.0ef31] Connection failed to broker: mqtt://localhost:1880

Any ideas to make this work ?