This properly belongs on the ssh group, but posting there has not gotten any responses... and the list is quite slow to boot.
I like using ssh -X to other lan remotes but with new versions of openssh or perhaps the configs, it only works 1 way. I can `ssh -X' to the gentoo host from a debian host but not the other way round. Two different versions of openssh appear to be involved. But not sure how different they are. RHOST=a debian HOST LHOST= Gentoo HOST ssh -vN $RHOST 2>&1|grep "remote software version" [...] OpenSSH_6.7p1 Debian-3 ssh -vN $LHOST 2>&1|grep "remote software version" [...] OpenSSH_6.7p1-hpn14v5 One thing I tried to do was to copy the RHOST sshd_config and ssh_config to LHOST. Restart and try again... there were a few incompatible bits in the files so after commenting a few out until no config errors. However ssh -X still displayed the error and would NOT work when: ssh -X RHOST from LHOST ({Note that plain ssh LHOST or RHOST works in any direction} Error outut with ssh -X $RHOST "xterm" ,---- | Warning: untrusted X11 forwarding setup failed: xauth key data not generated | Warning: No xauth data; using fake authentication data for X11 forwarding. | Invalid MIT-MAGIC-COOKIE-1 keyxterm: Xt error: Can't open display: localhost:10.0 `---- [Full Error output with ssh -vv -X is very lengthy so is attached at the end] I'm not seeing how to debug this further. So going back to the stock version of sshd_config ssh_config on gentoo with two changes: commented out this line: PasswordAuthentication no added this: X11Forwarding yes ------- ------- ---=--- ------- ------- Full sshd_config on LHOST: sudo grep ^[^#] /etc/ssh/sshd_config ------- ------- ---=--- ------- ------- UsePAM yes X11Forwarding yes PrintMotd no PrintLastLog no UsePrivilegeSeparation sandbox # Default for new installations. Subsystem sftp /usr/lib/misc/sftp-server AcceptEnv LANG LC_* ------- Config END ------- ------- ------- ---=--- ------- ------- Full ssh_config on LHOST: sudo grep ^[^#] /etc/ssh/ssh_config ------- ------- ---=--- ------- ------- ForwardX11 yes SendEnv LANG LC_* ------- Config END ------- ####################################################### Now the same info for RHOST ------- ------- ---=--- ------- ------- Full sshd_config on RHOST: ssh root@RHOST "grep ^[^#] /etc/ssh/sshd_config" ------- ------- ---=--- ------- ------- HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ed25519_key AcceptEnv LANG LC_* ChallengeResponseAuthentication no IgnoreRhosts yes HostbasedAuthentication no KeyRegenerationInterval 3600 LogLevel INFO LoginGraceTime 120 PermitEmptyPasswords no PermitRootLogin yes Port 22 PrintLastLog yes PrintMotd no Protocol 2 PubkeyAuthentication yes RSAAuthentication yes RhostsRSAAuthentication no ServerKeyBits 1024 SyslogFacility AUTH StrictModes yes Subsystem sftp /usr/lib/misc/sftp-server TCPKeepAlive yes UsePAM yes UsePrivilegeSeparation sandbox X11Forwarding yes ------- Config END ------- ------- ------- ---=--- ------- ------- Full ssh_config on RHOST: ssh root@RHOST "grep ^[^#] /etc/ssh/ssh_config" ------- ------- ---=--- ------- ------- Host * ForwardX11 yes SendEnv LANG LC_* HashKnownHosts yes ------- Config END ------- ############################################ ############################################ The only thing more I can think to include is the full lengthy output of ssh -vv -X
HOST:gv ~ harry > ssh -vv -X harry@dv 'xterm' OpenSSH_6.7p1-hpn14v5, OpenSSL 1.0.1j 15 Oct 2014 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 20: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to dv [192.168.0.5] port 22. debug1: Connection established. debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_rsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_rsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_dsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_dsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_ecdsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_ecdsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_ed25519 type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/harry/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.7p1-hpn14v5 debug1: Remote protocol version 2.0, remote software version OpenSSH_6.7p1 Debian-3 debug1: Remote is NON-HPN aware debug1: match: OpenSSH_6.7p1 Debian-3 pat OpenSSH* compat 0x24000000 debug2: fd 3 setting O_NONBLOCK debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: AUTH STATE IS 0 debug2: kex_parse_kexinit: curve25519-sha...@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-ed25519-cert-...@openssh.com,ssh-ed25519,ecdsa-sha2-nistp256-cert-...@openssh.com,ecdsa-sha2-nistp384-cert-...@openssh.com,ecdsa-sha2-nistp521-cert-...@openssh.com,ssh-rsa-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ssh-rsa-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-md5-...@openssh.com,hmac-ripemd160-...@openssh.com,hmac-sha1-96-...@openssh.com,hmac-md5-96-...@openssh.com,hmac-md5,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-md5-...@openssh.com,hmac-ripemd160-...@openssh.com,hmac-sha1-96-...@openssh.com,hmac-md5-96-...@openssh.com,hmac-md5,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,z...@openssh.com,zlib debug2: kex_parse_kexinit: none,z...@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-sha...@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss,ssh-ed25519 debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: kex_parse_kexinit: none,z...@openssh.com debug2: kex_parse_kexinit: none,z...@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 umac-64-...@openssh.com debug1: REQUESTED ENC.NAME is 'aes128-ctr' debug1: kex: server->client aes128-ctr umac-64-...@openssh.com none debug2: mac_setup: setup umac-64-...@openssh.com debug1: REQUESTED ENC.NAME is 'aes128-ctr' debug1: kex: client->server aes128-ctr umac-64-...@openssh.com none debug1: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: ED25519 78:0a:64:ae:48:55:a2:32:f2:ce:75:01:b4:ee:fa:21 debug1: Host 'dv' is known and matches the ED25519 host key. debug1: Found key in /home/harry/.ssh/known_hosts:2 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: /home/harry/.ssh/id_rsa ((nil)), debug2: key: /home/harry/.ssh/id_dsa ((nil)), debug2: key: /home/harry/.ssh/id_ecdsa ((nil)), debug2: key: /home/harry/.ssh/id_ed25519 ((nil)), debug1: Authentications that can continue: publickey,password debug1: Next authentication method: publickey debug1: Trying private key: /home/harry/.ssh/id_rsa debug1: Trying private key: /home/harry/.ssh/id_dsa debug1: Trying private key: /home/harry/.ssh/id_ecdsa debug1: Trying private key: /home/harry/.ssh/id_ed25519 debug2: we did not send a packet, disable method debug1: Next authentication method: password harry@dv's password: debug2: we sent a password packet, wait for reply debug1: Single to Multithread CTR cipher swap - client request debug1: Authentication succeeded (password). Authenticated to dv ([192.168.0.5]:22). debug1: HPN to Non-HPN Connection debug1: Final hpn_buffer_size = 2097152 debug1: HPN Disabled: 0, HPN Buffer Size: 2097152 debug1: channel 0: new [client-session] debug1: Enabled Dynamic Window Scaling debug2: channel 0: send open debug1: Requesting no-more-sessi...@openssh.com debug1: Entering interactive session. debug1: need rekeying debug1: SSH2_MSG_KEXINIT sent debug1: rekeying in progress debug2: callback start debug2: x11_get_proto: /usr/bin/xauth -f /tmp/ssh-qqfAyxQhvSOr/xauthfile generate :0.0 MIT-MAGIC-COOKIE-1 untrusted timeout 1200 2>/dev/null Warning: untrusted X11 forwarding setup failed: xauth key data not generated Warning: No xauth data; using fake authentication data for X11 forwarding. debug1: Requesting X11 forwarding with authentication spoofing. debug2: channel 0: request x11-req confirm 1 debug1: enqueue packet: 98 debug2: fd 3 setting TCP_NODELAY/SCTP_NODELAY debug2: client_session2_setup: id 0 debug1: Sending environment. debug1: Sending command: xterm debug2: channel 0: request exec confirm 1 debug1: enqueue packet: 98 debug2: callback done debug2: channel 0: open confirm rwindow 0 rmax 32768 debug1: SSH2_MSG_KEXINIT received debug1: AUTH STATE IS 1 debug2: kex_parse_kexinit: curve25519-sha...@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-ed25519-cert-...@openssh.com,ssh-ed25519,ecdsa-sha2-nistp256-cert-...@openssh.com,ecdsa-sha2-nistp384-cert-...@openssh.com,ecdsa-sha2-nistp521-cert-...@openssh.com,ssh-rsa-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ssh-rsa-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-md5-...@openssh.com,hmac-ripemd160-...@openssh.com,hmac-sha1-96-...@openssh.com,hmac-md5-96-...@openssh.com,hmac-md5,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-md5-...@openssh.com,hmac-ripemd160-...@openssh.com,hmac-sha1-96-...@openssh.com,hmac-md5-96-...@openssh.com,hmac-md5,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,z...@openssh.com,zlib debug2: kex_parse_kexinit: none,z...@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-sha...@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss,ssh-ed25519 debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: kex_parse_kexinit: umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-sha1-...@openssh.com,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: kex_parse_kexinit: none,z...@openssh.com debug2: kex_parse_kexinit: none,z...@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 umac-64-...@openssh.com debug1: REQUESTED ENC.NAME is 'aes128-ctr' debug1: kex: server->client aes128-ctr umac-64-...@openssh.com none debug2: mac_setup: setup umac-64-...@openssh.com debug1: REQUESTED ENC.NAME is 'aes128-ctr' debug1: kex: client->server aes128-ctr umac-64-...@openssh.com none debug1: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: ED25519 78:0a:64:ae:48:55:a2:32:f2:ce:75:01:b4:ee:fa:21 debug1: verify_host_key: server host key matches cached key debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: set_newkeys: rekeying debug1: spawned a thread debug1: spawned a thread debug1: dequeue packet: 98 debug1: dequeue packet: 98 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: set_newkeys: rekeying debug1: spawned a thread debug1: spawned a thread debug1: SSH2_MSG_NEWKEYS received debug2: tcpwinsz: 318720 for connection: 3 debug2: channel_input_status_confirm: type 99 id 0 debug2: X11 forwarding request accepted on channel 0 debug2: channel 0: rcvd adjust 2097152 debug2: channel_input_status_confirm: type 99 id 0 debug2: exec request accepted on channel 0 debug2: tcpwinsz: 318720 for connection: 3 debug1: client_input_channel_open: ctype x11 rchan 3 win 65536 max 16384 debug1: client_request_x11: request from 127.0.0.1 41191 debug2: fd 7 setting O_NONBLOCK debug1: channel 1: new [x11] debug1: confirm x11 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: channel 1: read<=0 rfd 7 len 0 debug2: channel 1: read failed debug2: channel 1: close_read debug2: channel 1: input open -> drain debug2: channel 1: ibuf empty debug2: channel 1: send eof debug2: channel 1: input drain -> closed debug2: tcpwinsz: 318720 for connection: 3 debug2: tcpwinsz: 318720 for connection: 3 debug2: channel 0: rcvd ext data 30 debug2: channel 1: rcvd eof debug2: channel 1: output open -> drain debug2: channel 1: obuf empty debug2: channel 1: close_write debug2: channel 1: output drain -> closed debug2: channel 0: rcvd ext data 7 debug2: tcpwinsz: 318720 for connection: 3 debug2: channel 1: send close Invalid MIT-MAGIC-COOKIE-1 keyxterm: debug2: channel 0: written 37 to efd 6 debug2: tcpwinsz: 318720 for connection: 3 debug2: channel 1: rcvd close debug2: channel 0: rcvd ext data 45 debug2: channel 0: rcvd eof debug2: channel 0: output open -> drain debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 debug1: client_input_channel_req: channel 0 rtype e...@openssh.com reply 0 debug2: channel 0: rcvd eow debug2: channel 0: close_read debug2: channel 0: input open -> closed debug2: channel 0: rcvd close debug2: tcpwinsz: 318720 for connection: 3 debug2: channel 0: obuf_empty delayed efd 6/(45) debug2: channel 1: is dead debug2: channel 1: garbage collecting debug1: channel 1: free: x11, nchannels 2 Xt error: Can't open display: localhost:10.0 debug2: channel 0: written 45 to efd 6 debug2: tcpwinsz: 318720 for connection: 3 debug2: channel 0: obuf empty debug2: channel 0: close_write debug2: channel 0: output drain -> closed debug2: channel 0: almost dead debug2: channel 0: gc: notify user debug2: channel 0: gc: user detached debug2: channel 0: send close debug2: channel 0: is dead debug2: channel 0: garbage collecting debug1: channel 0: free: client-session, nchannels 1 Transferred: sent 4756, received 2908 bytes, in 0.2 seconds Bytes per second: sent 30810.3, received 18838.6 debug1: Exit status 1