redmonhsu
By:
redmonhsu

After several days, SSH and SFTP no longer working. Connection closed by server.

September 24, 2015 1.5k views
Networking Linux Basics

I just got started with digital ocean and linux so I'm still learning the ropes. I set up a Ubuntu 14.04 x64 droplet a week ago and I was able to connect using ssh
user@ip via Cyberduck.
For some reason, I can't connect anymore although the login/password still works via Digital Ocean's console.

The response I get is "Connection closed by [server ip]"

Please help!

5 comments
  • Would you consider using Putty or even telnet? Ping the host from cmd line at your System. If it pings, then something is wrong at serverside (bruteforce, maybe?), if it is not, then the issue is at your PC, most likely to your IP.

  • Have you seen any notification from support about your networking being turned off for security reasons?

  • @saengbok what do you mean by ping host? I tried scanning and found the server's port 22 to be open. I've also tried connecting on two different computers on two different networks.

    @BrookDO I have not gotten any notifications for support.

    Not sure if this helps. here's the response to ssh -vvv:

    OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
    debug1: Reading configuration data /etc/ssh_config
    debug1: /etc/ssh_config line 20: Applying options for *
    debug2: ssh_connect: needpriv 0
    debug1: Connecting to website.com [159.203.xx.xx] port 22.
    debug1: Connection established.
    debug1: identity file /Users/john/.ssh/id_rsa type -1
    debug1: identity file /Users/john/.ssh/id_rsa-cert type -1
    debug1: identity file /Users/john/.ssh/id_dsa type -1
    debug1: identity file /Users/john/.ssh/id_dsa-cert type -1
    debug1: Enabling compatibility mode for protocol 2.0
    debug1: Local version string SSH-2.0-OpenSSH_6.2
    debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.3
    debug1: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.3 pat OpenSSH*
    debug2: fd 3 setting O_NONBLOCK
    debug3: load_hostkeys: loading entries for host "website.com" from file "/Users/john/.ssh/known_hosts"
    debug3: load_hostkeys: found key type RSA in file /Users/john/.ssh/known_hosts:2
    debug2: key_type_from_name: unknown key type 'ecdsa-sha2-nistp256'
    debug3: key_read: missing keytype
    debug3: load_hostkeys: loaded 1 keys
    debug3: order_hostkeyalgs: prefer hostkeyalgs: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa
    debug1: SSH2_MSG_KEXINIT sent
    debug1: SSH2_MSG_KEXINIT received
    debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
    debug2: kex_parse_kexinit: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa,ssh-dss-cert-v01@openssh.com,ssh-dss-cert-v00@openssh.com,ssh-dss
    debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
    debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
    debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
    debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
    debug2: kex_parse_kexinit: 
    debug2: kex_parse_kexinit: 
    debug2: kex_parse_kexinit: first_kex_follows 0 
    debug2: kex_parse_kexinit: reserved 0 
    debug2: kex_parse_kexinit: curve25519-sha256@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: kex_parse_kexinit: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ssh-ed25519
    debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
    debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
    debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
    debug2: kex_parse_kexinit: none,zlib@openssh.com
    debug2: kex_parse_kexinit: none,zlib@openssh.com
    debug2: kex_parse_kexinit: 
    debug2: kex_parse_kexinit: 
    debug2: kex_parse_kexinit: first_kex_follows 0 
    debug2: kex_parse_kexinit: reserved 0 
    debug2: mac_setup: found hmac-md5-etm@openssh.com
    debug1: kex: server->client aes128-ctr hmac-md5-etm@openssh.com none
    debug2: mac_setup: found hmac-md5-etm@openssh.com
    debug1: kex: client->server aes128-ctr hmac-md5-etm@openssh.com none
    debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
    debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
    debug2: dh_gen_key: priv key bits set: 124/256
    debug2: bits set: 516/1024
    debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
    debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
    debug1: Server host key: RSA 11:af:98:9e:aa:fe:08:5b:69:b2:ac:b7:b7:3e:2c:17
    debug3: load_hostkeys: loading entries for host "website.com" from file "/Users/john/.ssh/known_hosts"
    debug3: load_hostkeys: found key type RSA in file /Users/john/.ssh/known_hosts:2
    debug2: key_type_from_name: unknown key type 'ecdsa-sha2-nistp256'
    debug3: key_read: missing keytype
    debug3: load_hostkeys: loaded 1 keys
    debug3: load_hostkeys: loading entries for host "159.203.xx.xx" from file "/Users/john/.ssh/known_hosts"
    debug3: load_hostkeys: found key type RSA in file /Users/john/.ssh/known_hosts:1
    debug2: key_type_from_name: unknown key type 'ecdsa-sha2-nistp256'
    debug3: key_read: missing keytype
    debug3: load_hostkeys: loaded 1 keys
    debug1: Host 'website.com' is known and matches the RSA host key.
    debug1: Found key in /Users/john/.ssh/known_hosts:2
    debug2: bits set: 525/1024
    debug1: ssh_rsa_verify: signature correct
    debug2: kex_derive_keys
    debug2: set_newkeys: mode 1
    debug1: SSH2_MSG_NEWKEYS sent
    debug1: expecting SSH2_MSG_NEWKEYS
    debug2: set_newkeys: mode 0
    debug1: SSH2_MSG_NEWKEYS received
    debug1: Roaming not allowed by server
    debug1: SSH2_MSG_SERVICE_REQUEST sent
    debug2: service_accept: ssh-userauth
    debug1: SSH2_MSG_SERVICE_ACCEPT received
    debug2: key: /Users/john/.ssh/id_rsa (0x0),
    debug2: key: /Users/john/.ssh/id_dsa (0x0),
    debug1: Authentications that can continue: publickey,password,keyboard-interactive
    debug3: start over, passed a different list publickey,password,keyboard-interactive
    debug3: preferred publickey,keyboard-interactive,password
    debug3: authmethod_lookup publickey
    debug3: remaining preferred: keyboard-interactive,password
    debug3: authmethod_is_enabled publickey
    debug1: Next authentication method: publickey
    debug1: Trying private key: /Users/john/.ssh/id_rsa
    debug3: no such identity: /Users/john/.ssh/id_rsa: No such file or directory
    debug1: Trying private key: /Users/john/.ssh/id_dsa
    debug3: no such identity: /Users/john/.ssh/id_dsa: No such file or directory
    debug2: we did not send a packet, disable method
    debug3: authmethod_lookup keyboard-interactive
    debug3: remaining preferred: password
    debug3: authmethod_is_enabled keyboard-interactive
    debug1: Next authentication method: keyboard-interactive
    debug2: userauth_kbdint
    debug2: we sent a keyboard-interactive packet, wait for reply
    debug1: Authentications that can continue: publickey,password,keyboard-interactive
    debug3: userauth_kbdint: disable: no info_req_seen
    debug2: we did not send a packet, disable method
    debug3: authmethod_lookup password
    debug3: remaining preferred: 
    debug3: authmethod_is_enabled password
    debug1: Next authentication method: password
    root@website.com's password: 
    debug3: packet_send2: adding 64 (len 53 padlen 11 extra_pad 64)
    debug2: we sent a password packet, wait for reply
    Connection closed by 159.203.xx.xx
    
    
  • Hi,

    Hm. That is definitely strange. You can open a support ticket, and our team may be able to help you investigate the logs to determine what is occurring.

  • Ok, so I was wrong. Apparently, I was receiving notifications about security issues. :(

    This can be marked as resolved.

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