So I installed mosquitto and mosquitto-client on a Raspberry Pi running Raspbian Jessie through apt-get as well as mosquitto on another Pi running Arch Linux through pacman. On Arch the client utils do not need to be installed separately.
Testing simple subscription/publishing on Raspbian worked out of the box.
mosquitto_sub –d –t blub
mosquitto_pub –d –t blub –m “test”
Publishing from the Arch box works as well:
mosquitto_pub -h <IP-Raspbian> -t blub -m "test"
Subscribing a topic on the Arch system however gets me just:
mosquitto_sub –d –t blub
Error: Connection refused
Now that is pretty generic. What's wrong here?