My Rpi4 running my home automation recently upgraded itself from mosquitto version 1.6.12 to 2.0.8 and as a consequence it was starting in local only mode.
Done some digging about but still can't get it all working again, mainly used this previous helpful question Mosquitto: Starting in local only mode but my devices still can't connect.
From my mosquiito log I see
1614386087: mosquitto version 2.0.8 starting
1614386087: Config loaded from /etc/mosquitto/mosquitto.conf.
1614386087: Opening ipv4 listen socket on port 1883.
1614386087: Opening ipv6 listen socket on port 1883.
1614386087: mosquitto version 2.0.8 running
The service shows this
:~$ sudo systemctl status mosquitto
* mosquitto.service - Mosquitto MQTT Broker
Loaded: loaded (/lib/systemd/system/mosquitto.service; enabled; vendor preset: enabled)
Active: active (running) since Sat 2021-02-27 00:34:47 GMT; 10h ago
Docs: man:mosquitto.conf(5)
man:mosquitto(8)
Process: 375 ExecStartPre=/bin/mkdir -m 740 -p /var/log/mosquitto (code=exited, status=0/SUCCESS)
Process: 398 ExecStartPre=/bin/chown mosquitto: /var/log/mosquitto (code=exited, status=0/SUCCESS)
Process: 404 ExecStartPre=/bin/mkdir -m 740 -p /var/run/mosquitto (code=exited, status=0/SUCCESS)
Process: 411 ExecStartPre=/bin/chown mosquitto: /var/run/mosquitto (code=exited, status=0/SUCCESS)
Main PID: 419 (mosquitto)
Memory: 1.5M
CGroup: /system.slice/mosquitto.service
`-419 /usr/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf
Feb 27 00:34:47 Vero4K systemd[1]: Starting Mosquitto MQTT Broker...
Feb 27 00:34:47 Vero4K mosquitto[419]: 1614386087: Loading config file /etc/mosquitto/conf.d/calz.conf
Feb 27 00:34:47 Vero4K systemd[1]: Started Mosquitto MQTT Broker.
In my calz.conf file I have
listener 1883
allow_anonymous true
But my local version of Domoticz (runs on the same box) shows this in it's logs
Error: Plugin: Connection Exception: 'resolve: Host not found (authoritative)' connecting to '127.0.0.1:1883'
Error: (ShellyMQTT) Failed to connect to: 127.0.0.1:1883, Description: resolve: Host not found (authoritative)
And all my Tasmota devices now show
14:49:38 MQT: Attempting connection...
14:49:38 MQT: Connect failed to 192.168.1.19:1883, rc -2. Retry in 120 sec
I can see the port open as well
sudo netstat -tulpn | grep LISTEN
tcp 0 0 0.0.0.0:21 0.0.0.0:* LISTEN 361/vsftpd
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 729/sshd
tcp 0 0 0.0.0.0:37015 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:36666 0.0.0.0:* LISTEN 608/kodi.bin
tcp 0 0 0.0.0.0:36667 0.0.0.0:* LISTEN 608/kodi.bin
tcp 0 0 0.0.0.0:1883 0.0.0.0:* LISTEN 375/mosquitto
tcp 0 0 0.0.0.0:49472 0.0.0.0:* LISTEN 763/rpc.statd
tcp 0 0 0.0.0.0:9090 0.0.0.0:* LISTEN 608/kodi.bin
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 1/init
tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN 608/kodi.bin
tcp6 0 0 :::22 :::* LISTEN 729/sshd
tcp6 0 0 :::49079 :::* LISTEN 763/rpc.statd
tcp6 0 0 :::36666 :::* LISTEN 608/kodi.bin
tcp6 0 0 :::36667 :::* LISTEN 608/kodi.bin
tcp6 0 0 :::1883 :::* LISTEN 375/mosquitto
tcp6 0 0 :::49919 :::* LISTEN -
tcp6 0 0 :::9090 :::* LISTEN 608/kodi.bin
tcp6 0 0 :::111 :::* LISTEN 1/init
tcp6 0 0 :::8080 :::* LISTEN 608/kodi.bin
/etc/mosquitto/mosquitto.conf
# Place your local configuration in /etc/mosquitto/conf.d/
#
# A full description of the configuration file is at
# /usr/share/doc/mosquitto/examples/mosquitto.conf.example
pid_file /var/run/mosquitto/mosquitto.pid
persistence true
persistence_location /var/lib/mosquitto/
log_dest file /var/log/mosquitto/mosquitto.log
include_dir /etc/mosquitto/conf.d
Any ideas?