I have set up a home network behind a router a while ago and use openssh to access the network consisting of my laptop, wife's netbook and my desktop all running l/x/ubuntu 12.04. This worked perfectly for some time.
I am now only able to access from and to the netbook and the other 2, but no access between the laptop and desktop. I have never used the id_* route so have no id_* files in the ~/.ssh directories.
I have tried various strategies advised on forums such as this one eg. deleting the known_hosts and changing the configuration files such as the PasswordAuthentication to no, yes and commented out. None of which works.
The only thing I can think of is that my recent tinkering with setting up a vpn network between the laptop and desktop may have changed something to disrupt the working of ssh between these 2 machines. btw I have not managed to get the vpn to work yet (see previous post on this forum).
The /etc/ssh/sshd_config file on my desktop is:
# 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 internal-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 Match User sftpuser #group sftponly ChrootDirectory /media/Backups/ftp X11Forwarding yes AllowTcpForwarding yes ForceCommand internal-sftp
The ssh -v laptop command outputs:
OpenSSH_5.9p1 Debian-5ubuntu1.1, OpenSSL 1.0.1 14 Mar 2012 debug1: Reading configuration data /home/malapradej/.ssh/config debug1: /home/malapradej/.ssh/config line 1: Applying options for laptop debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug1: Connecting to 192.168.0.2 [192.168.0.2] port 22. debug1: Connection established. debug1: identity file /home/malapradej/.ssh/id_rsa type -1 debug1: identity file /home/malapradej/.ssh/id_rsa-cert type -1 debug1: identity file /home/malapradej/.ssh/id_dsa type -1 debug1: identity file /home/malapradej/.ssh/id_dsa-cert type -1 debug1: identity file /home/malapradej/.ssh/id_ecdsa type -1 debug1: identity file /home/malapradej/.ssh/id_ecdsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1.1 debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.1 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.1 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-md5 firstname.lastname@example.org debug1: kex: client->server aes128-ctr hmac-md5 email@example.com debug1: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: ECDSA 1e:f2:57:81:28:8a:12:d3:7e:2d:04:c2:82:4f:43:72 debug1: Host '192.168.0.2' is known and matches the ECDSA host key. debug1: Found key in /home/malapradej/.ssh/known_hosts:1 debug1: ssh_ecdsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey debug1: Next authentication method: publickey debug1: Trying private key: /home/malapradej/.ssh/id_rsa debug1: Trying private key: /home/malapradej/.ssh/id_dsa debug1: Trying private key: /home/malapradej/.ssh/id_ecdsa debug1: No more authentication methods to try. Permission denied (publickey).