SSh: Connection refused to localhost

Question

I want to install hadoop to ubuntu.

I'm following this tutorial: Running Hadoop on Ubuntu Linux

But i am facing a problem at step ssh localhost

hduser@r:~$ ssh -vvv localhost -p 8047
OpenSSH_6.2p2 Ubuntu-6ubuntu0.1, OpenSSL 1.0.1e 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to localhost [127.0.0.1] port 8047.
debug1: connect to address 127.0.0.1 port 8047: Connection refused
ssh: connect to host localhost port 8047: Connection refused

hduser@r:~$ which ssh
/usr/bin/ssh
hduser@r:~$ which sshd
hduser@r:~$ 

This is my /etc/ssh/sshd_config:

last 5 lines added only!

# Package generated configuration file
# See the sshd_config(5) manpage for details

# What ports, IPs and protocols we listen for
Port 22
# Use these options to restrict which interfaces/protocols sshd will bind to
#ListenAddress ::
#ListenAddress 0.0.0.0
Protocol 2
# HostKeys for protocol version 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
#Privilege Separation is turned on for security
UsePrivilegeSeparation yes

# Lifetime and size of ephemeral version 1 server key
KeyRegenerationInterval 3600
ServerKeyBits 768

# Logging
SyslogFacility AUTH
LogLevel INFO

# Authentication:
LoginGraceTime 120
PermitRootLogin yes
StrictModes yes

RSAAuthentication yes
PubkeyAuthentication yes
#AuthorizedKeysFile %h/.ssh/authorized_keys

# Don't read the user's ~/.rhosts and ~/.shosts files
IgnoreRhosts yes
# For this to work you will also need host keys in /etc/ssh_known_hosts
RhostsRSAAuthentication no
# similar for protocol version 2
HostbasedAuthentication no
# Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
#IgnoreUserKnownHosts yes

# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no

# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no

# Change to no to disable tunnelled clear text passwords
#PasswordAuthentication yes

# Kerberos options
#KerberosAuthentication no
#KerberosGetAFSToken no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

X11Forwarding yes
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
TCPKeepAlive yes
#UseLogin no

#MaxStartups 10:30:60
#Banner /etc/issue.net

# Allow client to pass locale environment variables
AcceptEnv LANG LC_*

Subsystem sftp /usr/lib/openssh/sftp-server

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes

AllowGroups hduser


# disable ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

thanks in advance (and also for not voting down :D ) )

EDIT:

hduser@r:~$ r@r:~$ netstat -tulpn

tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      -               
tcp        0      0 127.0.1.1:53            0.0.0.0:*               LISTEN      -               
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -               
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      -               
tcp        0      0 0.0.0.0:17500           0.0.0.0:*               LISTEN      -               
udp        0      0 127.0.1.1:53            0.0.0.0:*                           -               
udp        0      0 0.0.0.0:68              0.0.0.0:*                           -               
udp        0      0 0.0.0.0:631             0.0.0.0:*                           -               
udp        0      0 0.0.0.0:17500           0.0.0.0:*                           -               
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           -               
udp        0      0 0.0.0.0:26575           0.0.0.0:*                           -               
udp        0      0 0.0.0.0:47235           0.0.0.0:*                           -               
-         

Solution 1

Don't panic! Your command is incorrect.

ssh -vvv localhost -p 8047

The parameter -p 8047 means to reach port 8047, however SSH daemon runs at port 22. The config of sshd you pasted, has already proven my assumption.

You can try to access localhost via SSH by using

ssh hduser@localhost

Solution 2

you need to install openssh server

sudo apt-get install openssh-server

Comments

[ridvanzoro]

I update my question and add result of netstat -tulpn

[SS781]

The output of netstat shows which services are listening on which ports. Your posted output shows that there is nothing listening on port 8047, so it makes sense that you are getting a Connection refused error. If you really want to connect through that port, you need to have your sshd listen on it.

[ridvanzoro]

I know -p 8047 is wrong. But ssh hduser@localhost helped me to find problem.It gives Offending ECDSA key in /home/hduser/.ssh/known_hosts:1 remove with: ssh-keygen -f "/home/hduser/.ssh/known_hosts" -R localhost. Then it is working after ssh-keygen -f "/home/hduser/.ssh/known_hosts" -R localhost command.