Mosquitto is an open source message broker, It's a very lightweight uses a publish/subscribe messages. We have discussed  the Mosquitto installation on the previous post

this page explains how to install Moquitto manually latest version 1.4.8 on your Ubuntu or Debian system,

Open your terminal and execute the following commands step-by-step,
Step 1 : Create a new user and install requires packages:

# useradd mosquitto

# apt-get install git cmake  build-essential python quilt devscripts -y 

# apt-get install python-setuptools python3 libssl-dev gdb daemon uuid-dev libc-ares-dev -y  

Step 2 : Download and Extract Mosquitto

# wget

# tar -zxvf mosquitto-1.4.8.tar.gz

# cd mosquitto-1.4.8

Step 3 : Install Package:

# make

# make install

Step 4: Create a Softlink and start the MQTT service,

# ln -s /usr/local/sbin/mosquitto /usr/sbin/mosquitto

# mosquitto -c /etc/mosquitto/mosquitto.conf

By default MQTT running on port number 1883, to make ensure that port,

# netstat -anltp | grep 1883

tcp        0      0  *               LISTEN      3748/mosquitto  
tcp6       0      0 :::1883                 :::*                    LISTEN      3748/mosquitto