I want to control a no GUI Debian server by an X11 connection via ssh from Ubuntu desktop. From everything I read and watched it should work like a charm on Linux distros but it doesn't.
# The debian /etc/ssh/sshd_config: ... X11Forwarding yes X11DisplayOffset 10 X11UseLocalhost yes ... I did restart the sshd on debian after saving.
When I connect: ssh -X debian from Ubuntu (I have a config with port and user), after establishing connection and typing: gedit I get the following error:
user@debian:~$ gedit Unable to init server: Could not connect: Connection refused (gedit:26888): Gtk-WARNING **: 17:00:04.268: cannot open display: I have also openssh-server installed on Ubuntu with the same X11 configuration. I don't know if that is necessary but I tried anyway.
I have no clue what is needed for X11 to work between two Linux distros, from what I understand in X11 the roles are oposite and my Ubuntu desktop is now running (is supposed to run) an X11 server software which is supposed to come with ssh so I don't need to install anything and the Debian server is an X11 client.
Please help me connect and run GUI programs.
EDIT 1:
user@ubuntu:~$ ssh -X -vvv debian OpenSSH_8.3p1 Ubuntu-1ubuntu0.1, OpenSSL 1.1.1f 31 Mar 2020 debug1: Reading configuration data /home/*******/.ssh/config debug1: /home/*******/.ssh/config line 1: Applying options for debiando debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files debug1: /etc/ssh/ssh_config line 21: Applying options for * debug2: resolving ********* port ***** debug2: ssh_connect_direct debug1: Connecting to ************************ debug1: Connection established. debug1: identity file /home/*******/.ssh/***_id_rsa type 0 debug1: identity file /home/*******/.ssh/***_id_rsa-cert type -1 debug1: Local version string SSH-2.0-OpenSSH_8.3p1 Ubuntu-1ubuntu0.1 debug1: Remote protocol version 2.0, remote software version OpenSSH_7.9p1 Debian-10+deb10u2 debug1: match: OpenSSH_7.9p1 Debian-10+deb10u2 pat OpenSSH* compat 0x04000000 debug2: fd 3 setting O_NONBLOCK debug1: Authenticating to ***************** debug3: put_host_port: ******************* debug3: hostkeys_foreach: reading file "/home/*********/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /home/********/.ssh/known_hosts:5 debug3: load_hostkeys: loaded 1 keys from ************ debug3: order_hostkeyalgs: prefer hostkeyalgs: ,,,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521 debug3: send packet: type 20 debug1: SSH2_MSG_KEXINIT sent debug3: receive packet: type 20 debug1: SSH2_MSG_KEXINIT received debug2: local client KEXINIT proposal debug2: KEX algorithms: curve25519-sha256,,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c debug2: host key algorithms: ,,,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,,,,,,,,ssh-ed25519,,rsa-sha2-512,rsa-sha2-256,ssh-rsa debug2: ciphers ctos: ,aes128-ctr,aes192-ctr,aes256-ctr,, debug2: ciphers stoc: ,aes128-ctr,aes192-ctr,aes256-ctr,, debug2: MACs ctos: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none,,zlib debug2: compression stoc: none,,zlib debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug2: peer server KEXINIT proposal debug2: KEX algorithms: curve25519-sha256,,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1 debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 debug2: ciphers ctos: ,aes128-ctr,aes192-ctr,aes256-ctr,, debug2: ciphers stoc: ,aes128-ctr,aes192-ctr,aes256-ctr,, debug2: MACs ctos: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none, debug2: compression stoc: none, debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug1: kex: algorithm: curve25519-sha256 debug1: kex: host key algorithm: ecdsa-sha2-nistp256 debug1: kex: server->client cipher: MAC: <implicit> compression: none debug1: kex: client->server cipher: MAC: <implicit> compression: none debug3: send packet: type 30 debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug3: receive packet: type 31 debug1: Server host key: ecdsa-sha2-nistp256 SHA256:NvDOG/B9cRs6ML8cvw8BZ/Kv68dy52FwLKfYR69e4DA debug3: put_host_port: ************** debug3: put_host_port: ********************* debug3: hostkeys_foreach: reading file "/home/*******/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /home/*******/.ssh/known_hosts:5 debug3: load_hostkeys: loaded 1 keys from ************** debug3: hostkeys_foreach: reading file "/home/*******/.ssh/known_hosts" debug3: record_hostkey: found key type ECDSA in file /home/*******/.ssh/known_hosts:6 debug3: load_hostkeys: loaded 1 keys from ********************* debug1: Host '**************' is known and matches the ECDSA host key. debug1: Found key in /home/*******/.ssh/known_hosts:5 debug3: send packet: type 21 debug2: set_newkeys: mode 1 debug1: rekey out after 134217728 blocks debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug3: receive packet: type 21 debug1: SSH2_MSG_NEWKEYS received debug2: set_newkeys: mode 0 debug1: rekey in after 134217728 blocks debug1: Will attempt key: /home/*******/.ssh/****_id_rsa RSA SHA256:OmiK3okiaARnd7XRw4d+y/LUaPREzcujUo4C4Ac+Hp4 explicit agent debug1: Will attempt key: *******@KK-flash RSA SHA256:O6QLIsdS+t9UO0IyAsk14PaM+RQocYYcXlxf6CuK7UE agent debug2: pubkey_prepare: done debug3: send packet: type 5 debug3: receive packet: type 7 debug1: SSH2_MSG_EXT_INFO received debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521> debug3: receive packet: type 6 debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug3: send packet: type 50 debug3: receive packet: type 51 debug1: Authentications that can continue: publickey debug3: start over, passed a different list publickey debug3: preferred gssapi-with-mic,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: Offering public key: /home/*******/.ssh/*****_id_rsa RSA SHA256:OmiK3okiaARnd7XRw4d+y/LUaPREzcujUo4C4Ac+Hp4 explicit agent debug3: send packet: type 50 debug2: we sent a publickey packet, wait for reply debug3: receive packet: type 60 debug1: Server accepts key: /home/*******/.ssh/****_id_rsa RSA SHA256:OmiK3okiaARnd7XRw4d+y/LUaPREzcujUo4C4Ac+Hp4 explicit agent debug3: sign_and_send_pubkey: RSA SHA256:OmiK3okiaARnd7XRw4d+y/LUaPREzcujUo4C4Ac+Hp4 debug3: sign_and_send_pubkey: signing using rsa-sha2-512 SHA256:OmiK3okiaARnd7XRw4d+y/LUaPREzcujUo4C4Ac+Hp4 debug3: send packet: type 50 debug3: receive packet: type 52 debug1: Authentication succeeded (publickey). Authenticated to **************************** debug1: channel 0: new [client-session] debug3: ssh_session2_open: channel_new: 0 debug2: channel 0: send open debug3: send packet: type 90 debug1: Requesting debug3: send packet: type 80 debug1: Entering interactive session. debug1: pledge: exec debug3: receive packet: type 80 debug1: client_input_global_request: rtype want_reply 0 debug3: receive packet: type 4 debug1: Remote: /home/*******/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding debug3: receive packet: type 4 debug1: Remote: /home/*******/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding debug3: receive packet: type 91 debug2: channel_input_open_confirmation: channel 0: callback start debug2: x11_get_proto: /usr/bin/xauth list :1 2>/dev/null debug1: Requesting X11 forwarding with authentication spoofing. debug2: channel 0: request x11-req confirm 1 debug3: send packet: type 98 debug2: fd 3 setting TCP_NODELAY debug3: ssh_packet_set_tos: set IP_TOS 0x10 debug2: client_session2_setup: id 0 debug2: channel 0: request pty-req confirm 1 debug3: send packet: type 98 debug1: Sending environment. debug3: Ignored env SHELL debug3: Ignored env SESSION_MANAGER debug3: Ignored env QT_ACCESSIBILITY debug3: Ignored env COLORTERM debug3: Ignored env XDG_CONFIG_DIRS debug3: Ignored env XDG_MENU_PREFIX debug3: Ignored env GNOME_DESKTOP_SESSION_ID debug3: Ignored env MANDATORY_PATH debug1: Sending env LC_ADDRESS = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env GNOME_SHELL_SESSION_MODE debug1: Sending env LC_NAME = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env SSH_AUTH_SOCK debug3: Ignored env XMODIFIERS debug3: Ignored env DESKTOP_SESSION debug1: Sending env LC_MONETARY = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env SSH_AGENT_PID debug3: Ignored env GTK_MODULES debug3: Ignored env PWD debug3: Ignored env LOGNAME debug3: Ignored env XDG_SESSION_DESKTOP debug3: Ignored env XDG_SESSION_TYPE debug3: Ignored env GPG_AGENT_INFO debug3: Ignored env XAUTHORITY debug3: Ignored env WINDOWPATH debug3: Ignored env HOME debug3: Ignored env USERNAME debug3: Ignored env IM_CONFIG_PHASE debug1: Sending env LC_PAPER = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug1: Sending env LANG = en_US.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env LS_COLORS debug3: Ignored env XDG_CURRENT_DESKTOP debug3: Ignored env VTE_VERSION debug3: Ignored env GNOME_TERMINAL_SCREEN debug3: Ignored env QT_DEVICE_PIXEL_RATIO debug3: Ignored env LESSCLOSE debug3: Ignored env XDG_SESSION_CLASS debug3: Ignored env TERM debug1: Sending env LC_IDENTIFICATION = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env DEFAULTS_PATH debug3: Ignored env LESSOPEN debug3: Ignored env LIBVIRT_DEFAULT_URI debug3: Ignored env USER debug3: Ignored env GNOME_TERMINAL_SERVICE debug3: Ignored env DISPLAY debug3: Ignored env SHLVL debug1: Sending env LC_TELEPHONE = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env PT7HOME debug3: Ignored env QT_IM_MODULE debug1: Sending env LC_MEASUREMENT = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env XDG_RUNTIME_DIR debug1: Sending env LC_TIME = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env XDG_DATA_DIRS debug3: Ignored env PATH debug3: Ignored env GDMSESSION debug3: Ignored env DBUS_SESSION_BUS_ADDRESS debug1: Sending env LC_NUMERIC = pl_PL.UTF-8 debug2: channel 0: request env confirm 0 debug3: send packet: type 98 debug3: Ignored env GOPATH debug3: Ignored env _ debug2: channel 0: request shell confirm 1 debug3: send packet: type 98 debug2: channel_input_open_confirmation: channel 0: callback done debug2: channel 0: open confirm rwindow 0 rmax 32768 debug3: receive packet: type 4 debug1: Remote: No xauth program; cannot forward X11. debug3: receive packet: type 100 debug2: channel_input_status_confirm: type 100 id 0 X11 forwarding request failed on channel 0 debug3: receive packet: type 99 debug2: channel_input_status_confirm: type 99 id 0 debug2: PTY allocation request accepted on channel 0 debug2: channel 0: rcvd adjust 2097152 debug3: receive packet: type 99 debug2: channel_input_status_confirm: type 99 id 0 debug2: shell request accepted on channel 0 Linux debianserver 4.19.0-16-cloud-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19) x86_64 The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. Last login: Wed Jun 16 17:19:01 2021 from 83.4.50.208 kDeb:~$ debug2: client_check_window_change: changed debug2: channel 0: request window-change confirm 0 debug3: send packet: type 98 debug2: client_check_window_change: changed debug2: channel 0: request window-change confirm 0 debug3: send packet: type 98 1 Answer
Answer:
Install xauth on both sides: sudo apt-get install xauth.
To find what is wrong turn on debugging with ssh it is done by:
using switches -v, -vv and -vvv where the last gives the most in-depth info.
By using the first switch at the end of debug messages I found:
debug1: Remote: No xauth program; cannot forward X11. Which was the answer.
