I use ubuntu 14.04 and I connect through SSH to a dozen odd servers both physical machines and virtual ones on the cloud.
On one of my servers I used to connect through an RSA Authentication Key, I could connect to the server both as a user as well as root. But within few seconds, the ssh session hangs.
This behavior is observed only from my machine. I tested connecting to the same server from windows (through putty) as well as a linux server through xterm. Both were successful and was working normally.
From my machine where I have this problem, I am still able to connect with the rest of the other servers, without any trouble.
I couldn't figure out what could be the possible issue with this particular server?
The server uses RHEL 6.8.
The following is the verbose error output:
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 192.168.1.192 [192.168.1.192] port 22.
debug1: Connection established.
debug3: Incorrect RSA1 identifier
debug3: Could not load "/home/ir_comp_N232/.ssh/id_rsa" as a RSA1 public key
debug1: identity file /home/ir_comp_N232/.ssh/id_rsa type 1
debug1: identity file /home/ir_comp_N232/.ssh/id_rsa-cert type -1
debug1: identity file /home/ir_comp_N232/.ssh/id_dsa type -1
debug1: identity file /home/ir_comp_N232/.ssh/id_dsa-cert type -1
debug1: identity file /home/ir_comp_N232/.ssh/id_ecdsa type -1
debug1: identity file /home/ir_comp_N232/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/ir_comp_N232/.ssh/id_ed25519 type -1
debug1: identity file /home/ir_comp_N232/.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-2ubuntu2.10
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH_5* compat 0x0c000000
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "192.168.1.192" from file "/home/ir_comp_N232/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /home/ir_comp_N232/.ssh/known_hosts:3
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: 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-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ssh-ed25519-cert-v01@openssh.com,ssh-dss-cert-v01@openssh.com,ssh-dss-cert-v00@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,ssh-dss
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,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: 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
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,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-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@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,hmac-sha1,umac-64@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: setup hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_setup: setup hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<3072<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: bits set: 1541/3072
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA 44:95:bf:bf:90:04:aa:72:80:77:17:29:84:42:3e:48
debug3: load_hostkeys: loading entries for host "192.168.1.192" from file "/home/ir_comp_N232/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /home/ir_comp_N232/.ssh/known_hosts:3
debug3: load_hostkeys: loaded 1 keys
debug1: Host '192.168.1.192' is known and matches the RSA host key.
debug1: Found key in /home/ir_comp_N232/.ssh/known_hosts:3
debug2: bits set: 1531/3072
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: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/ir_comp_N232/.ssh/id_rsa (0x55627af25490),
debug2: key: /home/ir_comp_N232/.ssh/id_dsa ((nil)),
debug2: key: /home/ir_comp_N232/.ssh/id_ecdsa ((nil)),
debug2: key: /home/ir_comp_N232/.ssh/id_ed25519 ((nil)),
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic,password
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup gssapi-keyex
debug3: remaining preferred: gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-keyex
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug2: we did not send a packet, disable method
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available
debug1: Unspecified GSS failure. Minor code may provide more information
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available
debug2: we did not send a packet, disable method
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/ir_comp_N232/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug2: input_userauth_pk_ok: fp 11:4a:69:3f:dc:51:40:cf:b4:0d:8a:29:0b:8f:80:2d
debug3: sign_and_send_pubkey: RSA 11:4a:69:3f:dc:51:40:cf:b4:0d:8a:29:0b:8f:80:2d
debug1: Authentication succeeded (publickey).
Authenticated to 192.168.1.192 ([192.168.1.192]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug2: callback start
debug2: fd 3 setting TCP_NODELAY
debug3: packet_set_tos: set IP_TOS 0x10
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug1: Sending environment.
debug3: Ignored env XDG_VTNR
debug3: Ignored env XDG_SESSION_ID
debug3: Ignored env XDG_GREETER_DATA_DIR
debug3: Ignored env SELINUX_INIT
debug3: Ignored env VIRTUALENVWRAPPER_PROJECT_FILENAME
debug3: Ignored env VIRTUALENVWRAPPER_SCRIPT
debug3: Ignored env CLUTTER_IM_MODULE
debug3: Ignored env SESSION
debug3: Ignored env GPG_AGENT_INFO
debug3: Ignored env TERM
debug3: Ignored env VTE_VERSION
debug3: Ignored env XDG_MENU_PREFIX
debug3: Ignored env SHELL
debug3: Ignored env WINDOWID
debug3: Ignored env UPSTART_SESSION
debug3: Ignored env GNOME_KEYRING_CONTROL
debug3: Ignored env GTK_MODULES
debug3: Ignored env NO_PROXY
debug3: Ignored env USER
debug3: Ignored env LD_LIBRARY_PATH
debug3: Ignored env XDG_SESSION_PATH
debug3: Ignored env XDG_SEAT_PATH
debug3: Ignored env SSH_AUTH_SOCK
debug3: Ignored env DEFAULTS_PATH
debug3: Ignored env SESSION_MANAGER
debug3: Ignored env WORKON_HOME
debug3: Ignored env XDG_CONFIG_DIRS
debug3: Ignored env VIRTUALENVWRAPPER_PYTHON
debug3: Ignored env DESKTOP_SESSION
debug3: Ignored env PATH
debug3: Ignored env QT_IM_MODULE
debug3: Ignored env VIRTUALENVWRAPPER_HOOK_DIR
debug3: Ignored env QT_QPA_PLATFORMTHEME
debug3: Ignored env PWD
debug3: Ignored env JOB
debug3: Ignored env XMODIFIERS
debug3: Ignored env GNOME_KEYRING_PID
debug1: Sending env LANG = en_IN
debug2: channel 0: request env confirm 0
debug3: Ignored env GDM_LANG
debug3: Ignored env MANDATORY_PATH
debug3: Ignored env COMPIZ_CONFIG_PROFILE
debug3: Ignored env IM_CONFIG_PHASE
debug3: Ignored env GDMSESSION
debug3: Ignored env SESSIONTYPE
debug3: Ignored env SHLVL
debug3: Ignored env HOME
debug3: Ignored env XDG_SEAT
debug3: Ignored env LANGUAGE
debug3: Ignored env no_proxy
debug3: Ignored env GNOME_DESKTOP_SESSION_ID
debug3: Ignored env LOGNAME
debug3: Ignored env COMPIZ_BIN_PATH
debug3: Ignored env DBUS_SESSION_BUS_ADDRESS
debug3: Ignored env XDG_DATA_DIRS
debug3: Ignored env QT4_IM_MODULE
debug3: Ignored env VIRTUALENVWRAPPER_WORKON_CD
debug3: Ignored env INSTANCE
debug3: Ignored env TEXTDOMAIN
debug3: Ignored env XDG_RUNTIME_DIR
debug3: Ignored env DISPLAY
debug3: Ignored env XDG_CURRENT_DESKTOP
debug3: Ignored env GTK_IM_MODULE
debug3: Ignored env TEXTDOMAINDIR
debug3: Ignored env XAUTHORITY
debug3: Ignored env COLORTERM
debug3: Ignored env _
debug2: channel 0: request shell confirm 1
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0
Though I could see the errors related to RSA key, the machine eventually logs into the server, post which it hangs.
