I have set up port forwarding but still get 'connection refused' from putty. One thing I have noticed is that if I log on to my web server and type sudo /usr/sbin/sshd -d I get the following errors: debug1: Bind to port 22 pm 0.0.0.0 Bind to port 22 on 0.0.0.0 failed: Address already in use. Debug1: Bind to port 22 on:. Secure Shell (SSH), secure logins, file transfers (scp, sftp) and port forwarding 23: Yes: Assigned: Telnet protocol—unencrypted text communications: 25: Yes: Assigned: Simple Mail Transfer Protocol (SMTP), used for email routing between mail servers 28: Unofficial: Palo Alto Networks' Panorama High Availability (HA) sync encrypted port.
This topic covers the Windows-specific configuration for OpenSSH Server (sshd).
Either edit /etc/ssh/sshdconfig & don't forget to restart SSH (service sshd restart) or leave it on 22, but forward port 26 on the router to port 22 on the second machine. Also, don't forget to change any firewall settings on the second machine to allow the connections through. By default, SSH runs on port 22. A port is simply a communication endpoint where a process is routed once it arrives on a server. To connect through SSH, a user requires the port number (e.g. 22 in this case) and a public IP address of the server alongside a username and a password.
OpenSSH maintains detailed documentation for configuration options online at OpenSSH.com, which is not duplicated in this documentation set.
Ssh Server Port
Configuring the default shell for OpenSSH in Windows
The default command shell provides the experience a user sees when connecting to the server using SSH.The initial default Windows is the Windows Command shell (cmd.exe).Windows also includes PowerShell and Bash, and third party command shells are also available for Windows and may be configured as the default shell for a server.
To set the default command shell, first confirm that the OpenSSH installation folder is on the system path.For Windows, the default installation folder is SystemDrive:WindowsDirectorySystem32openssh.The following commands shows the current path setting, and add the default OpenSSH installation folder to it.
|Command shell||Command to use|
Ssh Web Server Port
Configuring the default ssh shell is done in the Windows registry by adding the full path to the shell executable to ComputerHKEY_LOCAL_MACHINESOFTWAREOpenSSH in the string value DefaultShell.
As an example, the following Powershell command sets the default shell to be PowerShell.exe:
Windows Configurations in sshd_config
In Windows, sshd reads configuration data from %programdata%sshsshd_config by default, or a different configuration file may be specified by launching sshd.exe with the -f parameter.If the file is absent, sshd generates one with the default configuration when the service is started.
The elements listed below provide Windows-specific configuration possible through entries in sshd_config.There are other configuration settings possible in that are not listed here, as they are covered in detail in the online Win32 OpenSSH documentation.
AllowGroups, AllowUsers, DenyGroups, DenyUsers
Controlling which users and groups can connect to the server is done using the AllowGroups, AllowUsers, DenyGroups and DenyUsers directives.The allow/deny directives are processed in the following order: DenyUsers, AllowUsers, DenyGroups, and finally AllowGroups.All account names must be specified in lower case.See PATTERNS in ssh_config for more information on patterns for wildcards.
When configuring user/group based rules with a domain user or group, use the following format:
user?domain*.Windows allows multiple of formats for specifying domain principals, but many conflict with standard Linux patterns.For that reason, * is added to cover FQDNs.Also, this approach uses '?', instead of @, to avoid conflicts with the [email protected] format.
Work group users/groups and internet-connected accounts are always resolved to their local account name (no domain part, similar to standard Unix names).Domain users and groups are strictly resolved to NameSamCompatible format - domain_short_nameuser_name.All user/group based configuration rules need to adhere to this format.
Examples for domain users and groups
Examples for local users and groups
For Windows OpenSSH, the only available authentication methods are 'password' and 'publickey'.
The default is '.ssh/authorized_keys .ssh/authorized_keys2'. If the path is not absolute, it is taken relative to user's home directory (or profile image path). Ex. c:usersuser. Note that if the user belongs to the administrator group, %programdata%/ssh/administrators_authorized_keys is used instead.
Ssh Server Linux
ChrootDirectory (Support added in v220.127.116.11)
This directive is only supported with sftp sessions. A remote session into cmd.exe wouldn't honor this. To setup a sftp-only chroot server, set ForceCommand to internal-sftp. You may also set up scp with chroot, by implementing a custom shell that would only allow scp and sftp.
The defaults are %programdata%/ssh/ssh_host_ecdsa_key, %programdata%/ssh/ssh_host_ed25519_key, %programdata%/ssh/ssh_host_dsa_key, and %programdata%/ssh/ssh_host_rsa_key. If the defaults are not present, sshd automatically generates these on a service start.
Note that pattern rules in this section. User and group names should be in lower case.
Not applicable in Windows. To prevent administrator login, use Administrators with DenyGroups directive.
If you need file based logging, use LOCAL0. Logs are generated under %programdata%sshlogs.For any other value, including the default value, AUTH directs logging to ETW. For more info, see Logging Facilities in Windows.
The following configuration options are not available in the OpenSSH version that ships in Windows Server 2019 and Windows 10 1809:
Web Server Port Ssh