How to reconnect to a disconnected ssh session on Linux based SSH Server

Whenever we run a very long jobs on server over ssh, then sometimes the ssh-session will disconnected for various reasons. And when we again try connect to the server, then it will start another ssh-session. Now at that situation reconnect to a disconnected ssh session with the help of tmux utility. tmux is a terminal multiplexer, which can be used to multiplex several virtual consoles, allowing a user to access multiple separate terminal sessions inside a single terminal window or remote terminal session. It is useful for dealing with multiple programs from a command-line interface, and for separating programs from the Unix shell that started the program. First install tmux in your system if it not installed.
 $ sudo apt-get install tmux
 So, in order to make your ssh-session capable to reconnect, first connect to your ssh-server

 $ ssh test@ubuntusrv
 test@ubuntusrv's password:
 $
After the connection start tmux
 $ tmux
Now start your jobs or whatever you want. For example i am downloading ubuntu iso.
 $ wget http://mirrors.piconets.webwerks.in/ubuntureleases/16.04.3/ubuntu-16.04.3-desktop-amd64.iso
 --2017-12-28 10:18:54--  http://mirrors.piconets.webwerks.in/ubuntureleases/16.04.3/ubuntu-16.04.3-desktop-amd64.iso
 Resolving mirrors.piconets.webwerks.in (mirrors.piconets.webwerks.in)... 43.240.66.200
 Connecting to mirrors.piconets.webwerks.in (mirrors.piconets.webwerks.in)|43.240.66.200|:80... connected.
 HTTP request sent, awaiting response... 200 OK
 Length: 1587609600 (1.5G) [application/octet-stream]
 Saving to: ‘ubuntu-16.04.3-desktop-amd64.iso’

ubuntu-16.04.3-desktop-amd64.iso   0%[                   ]   3.43M  51.1KB/s    eta 9h 7m
Now i forcefully disconnected the session. Now again ssh into your server
 $ ssh test@ubuntusrv
 test@ubuntusrv's password:
 $
And then type 'tmux ls' command, which list all sessions managed by the server
 $ tmux ls
 0: 1 windows (created Thu Dec 28 10:25:47 2017) [197x53] (attached)
our session id is 0. To connect session 0 type
 $ tmux attach -t <session_id>

 $ tmux attach -t 0
 $ wget http://mirrors.piconets.webwerks.in/ubuntureleases/16.04.3/ubuntu-16.04.3-desktop-amd64.iso
 --2017-12-28 10:18:54--  http://mirrors.piconets.webwerks.in/ubuntureleases/16.04.3/ubuntu-16.04.3-desktop-amd64.iso
 Resolving mirrors.piconets.webwerks.in (mirrors.piconets.webwerks.in)... 43.240.66.200
 Connecting to mirrors.piconets.webwerks.in (mirrors.piconets.webwerks.in)|43.240.66.200|:80... connected.
 HTTP request sent, awaiting response... 200 OK
 Length: 1587609600 (1.5G) [application/octet-stream]
 Saving to: ‘ubuntu-16.04.3-desktop-amd64.iso’
 ubuntu-16.04.3-desktop-amd64.iso.  1%[>                 ]  16.42M  43.5KB/s    eta 9h 32m
and Thats it.


Check out our other posts about SSH :

How to install OpenSSH Server on Ubuntu Linux 16.04
How to Set up SSH keys on a linux based Client/Server
A Beginners Guide To SSH : How to start with SSH