Mosquitto realized MQTT v3.1 is a protocol of open source message broker software, including server-side and client-side, cross-platform deployment, provide lightweight support publish / subscribe messaging push mode, the device equipment short message communications between ease of use. The following is in Ubuntu16.04 environment, local MQTT build server and client:
First, install mosquitto
1.1 introduced mosquitto warehouse and updates
sudo apt-add-repository ppa:mosquitto-dev/mosquitto-ppa
sudo apt-get update
1.2 server and client installation mosquitto
sudo apt-get install mosquitto
sudo apt-get install mosquitto-clients
1.3 start / stop service mosquitto
sudo service mosquitto start
sudo service mosquitto stop
1.4 View service status mosquitto
sudo service mosquitto status (on behalf of a running start)
Second, the test
2.1 Open a terminal, subscribe to topics
mosquitto_sub -h localhost -t "mqtt" -v
[-H] Specifies the server to connect to MQTT
[-t] subscribe to a topic, here mqtt
[-v] prints more debugging information
2.2 Open another terminal, post a topic
mosquitto_pub -h localhost -t "mqtt" -m "Hello MQTT"
[-H] Specifies the server to connect to MQTT
[-t] push messages to the designated topic
[-m] specifies the message content
2.3 and use wireshark capture tool for MQTT protocol field in-depth analysis, the following is the command-line installation under Ubuntu 16.04 wireshark steps:
https://www.linuxidc.com/Linux/2016-08/134526.htm