x forwarding issue

Hi Luis,

thanks for the reply.

When you say X-Windows, you mean 'xclock'?

I'm using 'xclock' to see if x forwarding is working or not. I thought 'xclock' is widely used as a sort of test case to check x forwarding connections.

The main issue is that x forwarding is not working when I ssh from my mac to a Linux PC.

Sorry for the confusion.

Hi Luis,

Sorry for the confusion.

What I mean by "mac terminal" is, as you said, the one lives in /Applications/Utilities.

I'm testing 'xclock' on both "mac terminal" and Xquartz's terminal.

Yes, I don't think "xclock" is installed on mac by default. But, to my understanding, once we install XQuartz, "xclock" command should work because, I think, it's XQuartz that helps run "xclock"?

Thank you for the help Luis.

Hi Bob,

Thanks for the reply. I think I saw one of your posts about the issue related to this.

After I ssh to a Linux PC from my mac (following your command) and type "xclock" on the mac terminal, I get this:

connect /private/tmp/com.apple.launchd.DThrXUoAdi/org.xquartz:0: Connection refused
Error: Can't open display: localhost:12.0

Note that X forwarding works fine on XQuartz's terminal.

Do you mind sharing the configuration of your

/etc/ssh/ssh_config , /etc/ssh/sshd_config, /.ssh/config 

files?

I'm not sure if this is expected but, at first, all the lines were commented out except one or two in all the files (except /.ssh/config. This file's configuration was set up when I sshed on vscode I think) in my case.

These are mine.

sshd_config

#   $OpenBSD: sshd_config,v 1.104 2021/07/02 05:11:21 dtucker Exp $


# This is the sshd server system-wide configuration file.  See
# sshd_config(5) for more information.


# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin


# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options override the
# default value.


# This Include directive is not part of the default sshd_config shipped with
# OpenSSH. Options set in the included configuration files generally override
# those that follow.  The defaults only apply to options that have not been
# explicitly set.  Options that appear multiple times keep the first value set,
# unless they are a multivalue option such as HostKey.
Include /etc/ssh/sshd_config.d/*


#Port 22
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::


#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_ecdsa_key
#HostKey /etc/ssh/ssh_host_ed25519_key


# Ciphers and keying
#RekeyLimit default none


# Logging
#SyslogFacility AUTH
#LogLevel INFO


# Authentication:


#LoginGraceTime 2m
#PermitRootLogin prohibit-password
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10


#PubkeyAuthentication yes


# The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2
# but this is overridden so installations will only check .ssh/authorized_keys
AuthorizedKeysFile  .ssh/authorized_keys


#AuthorizedPrincipalsFile none


#AuthorizedKeysCommand none
#AuthorizedKeysCommandUser nobody


# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes


# To disable tunneled clear text passwords, change to no here!
#PasswordAuthentication yes
#PermitEmptyPasswords no


# Change to no to disable s/key passwords
#KbdInteractiveAuthentication yes


# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no


# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes


# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the KbdInteractiveAuthentication and
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via KbdInteractiveAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and KbdInteractiveAuthentication to 'no'.
#UsePAM no


#AllowAgentForwarding yes
#AllowTcpForwarding yes
#GatewayPorts no
X11Forwarding yes
X11DisplayOffset 10
#X11UseLocalhost yes
#PermitTTY yes
#PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#UseDNS no
#PidFile /var/run/sshd.pid
#MaxStartups 10:30:100
#PermitTunnel no
#ChrootDirectory none
#VersionAddendum none


# no default banner path
#Banner none


# override default of no subsystems
#Subsystem  sftp    /usr/libexec/sftp-server


# Example of overriding settings on a per-user basis
#Match User anoncvs
#   X11Forwarding no
#   AllowTcpForwarding no
#   PermitTTY no
#   ForceCommand cvs server


# XAuthLocation added by XQuartz (https://www.xquartz.org)
XAuthLocation /opt/X11/bin/xauth

ssh_config

#   $OpenBSD: ssh_config,v 1.35 2020/07/17 03:43:42 dtucker Exp $


# This is the ssh client system-wide configuration file.  See
# ssh_config(5) for more information.  This file provides defaults for
# users, and the values can be changed in per-user configuration files
# or on the command line.


# Configuration data is parsed as follows:
#  1. command line options
#  2. user-specific file
#  3. system-wide file
# Any configuration value is only changed the first time it is set.
# Thus, host-specific definitions should be at the beginning of the
# configuration file, and defaults at the end.


# This Include directive is not part of the default ssh_config shipped with
# OpenSSH. Options set in the included configuration files generally override
# those that follow.  The defaults only apply to options that have not been
# explicitly set.  Options that appear multiple times keep the first value set,
# unless they are a multivalue option such as IdentityFile.
Include /etc/ssh/ssh_config.d/*


# Site-wide defaults for some commonly used options.  For a comprehensive
# list of available options, their meanings and defaults, please see the
# ssh_config(5) man page.


Host *
    ForwardAgent yes
    ForwardX11 yes
#   PasswordAuthentication yes
#   HostbasedAuthentication no
#   GSSAPIAuthentication no
#   GSSAPIDelegateCredentials no
#   BatchMode no
#   CheckHostIP yes
    AddressFamily any
#   ConnectTimeout 0
#   StrictHostKeyChecking ask
#   IdentityFile ~/.ssh/id_rsa
#   IdentityFile ~/.ssh/id_dsa
#   IdentityFile ~/.ssh/id_ecdsa
#   IdentityFile ~/.ssh/id_ed25519
#   Port 22
#   Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc
#   MACs hmac-md5,hmac-sha1,umac-64@openssh.com
#   EscapeChar ~
#   Tunnel no
#   TunnelDevice any:any
#   PermitLocalCommand no
#   VisualHostKey no
#   ProxyCommand ssh -q -W %h:%p gateway.example.com
#   RekeyLimit 1G 1h
#   UserKnownHostsFile ~/.ssh/known_hosts.d/%k
Host *
    SendEnv LANG LC_*


# XAuthLocation added by XQuartz (https://www.xquartz.org)
Host *
    XAuthLocation /opt/X11/bin/xauth
    ForwardX11 yes

Hi etresoft,

thanks for the reply.

It's x forwarding that's not working in my case. ssh works.

when you run "xclock" or "xeyes", do they work? do they pop up linux windows on your MBA?

Thanks for the help

EDIT: oh you said you can run Firefox. Ok. That means you can see Linux Firefox window on your MBA. Thanks.

Hi Bob,

Appreciate your reply.

Just a quick check.

Do you use xterm (XQuartz terminal) for x forwarding? or mac built-in terminal? So, for example, when you tested "xclock", did you test it on xterm or mac's built-in terminal?

Hi etresoft,

just a quick question.

Did you use mac terminal? or XQuartz terminal?

If it was XQuartz's, could you try mac terminal also? It's the mac one that's not working for me.

Thank you Bob.

I appreciate it.