A conexão recusou o erro ao gerar a chave ssh

Question

Este é o erro que ocorre quando estou gerando a chave ssh.

hadoop1@hitesh-VGN-CS25GN-B:~$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
hadoop1@hitesh-VGN-CS25GN-B:~$ chmod 0600 ~/.ssh/authorized_keys
hadoop1@hitesh-VGN-CS25GN-B:~$ ssh localhost
ssh: connect to host localhost port 22: Connection refused

hadoop1@hitesh-VGN-CS25GN-B:~$ dpkg -l openssh-server
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version      Architecture Description
+++-==============-============-============-===============‌​==================
un  openssh-server <none>       <none>       (no description available)

hadoop1@hitesh-VGN-CS25GN-B:~$ service ssh status
● ssh.service
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)