My cases of this bug (though it seems like there are different ones with similar symptoms) happen each time I reset a 14.04 VM to an older state from a hard shutdown. Localhost ssh connections fail as well with same output.
Workaround for me is regenerating the host keys (sudo rm /etc/ssh/host_* && sudo ssh-keygen -A) each time I revert the VM. Changing the cipher/kex does not seem to change the outcome. I wonder if some junk gets written to the keys in bad shutdowns. I'll see If I can debug the output of the sshd. Client log below: $ ssh root@redacted -vvvv OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014 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 192.168.56.101 [192.168.56.101] port 22. debug1: Connection established. debug3: Incorrect RSA1 identifier debug3: Could not load "/home/sg/.ssh/id_rsa" as a RSA1 public key debug1: identity file /home/sg/.ssh/id_rsa type 1 debug1: identity file /home/sg/.ssh/id_rsa-cert type -1 debug1: identity file /home/sg/.ssh/id_dsa type -1 debug1: identity file /home/sg/.ssh/id_dsa-cert type -1 debug1: identity file /home/sg/.ssh/id_ecdsa type -1 debug1: identity file /home/sg/.ssh/id_ecdsa-cert type -1 debug1: identity file /home/sg/.ssh/id_ed25519 type -1 debug1: identity file /home/sg/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6p1 Ubuntu-2ubuntu1 debug1: match: OpenSSH_6.6p1 Ubuntu-2ubuntu1 pat OpenSSH_6.5*,OpenSSH_6.6* compat 0x14000000 debug2: fd 3 setting O_NONBLOCK debug3: load_hostkeys: loading entries for host "192.168.56.101" from file "/home/sg/.ssh/known_hosts" debug3: load_hostkeys: found key type ECDSA in file /home/sg/.ssh/known_hosts:87 debug3: load_hostkeys: loaded 1 keys debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-...@openssh.com,ecdsa-sha2-nistp384-cert-...@openssh.com,ecdsa-sha2-nistp521-cert-...@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521 debug2: compat_kex_proposal: original KEX proposal: curve25519-sha...@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: Compat: skipping algorithm "curve25519-sha...@libssh.org" debug2: compat_kex_proposal: compat KEX proposal: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug1: SSH2_MSG_KEXINIT sent Read from socket failed: Connection reset by peer -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/708493 Title: Can't login anymore: Read from socket failed: Connection reset by peer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/708493/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs