1. Check Ssh Server Status Ubuntu
2. Check Ssh Server Status

Your SSH server need to be restarted for any changes to take effect. If you're editing your sshd_config file from an SSH connection, any misconfiguration would mean you yourself will be locked out from the server as the SSHd service fails to start and will not be able to further fix the configuration issue.

SSHd has a test mode where it will only check the validity of your SSH server configuration file and immediately exit. It will display errors if there are any, and you can continue to make changes until there are no more errors.

Steps to test OpenSSH configuration file:

• Ssh-keygen -b 4096 -t rsa -C 'monitor@$ (hostname) user for checkbyssh' -N ' -f /opt/monitor/.ssh/idrsacheckbyssh When you are asked for a passphrase for the new ssh-keys do not add a password, just press Enter. Generating public/private rsa key pair. Your identification has been saved in /opt/monitor/.ssh/idrsacheckbyssh.
• To get the key length of your server key (s), you can use ssh-keygen: ssh-keygen -lf /etc/ssh/sshhostrsakey.pub but you will probably want also the moduli sizes that are offered and used during the key exchange, but it really depends on the key exchange method, but it should be also readable from debug output ssh -vvv host.

Enter a hostname or IP address below to check the server's SSH capabilities: This free SSH testing tool checks the configuration of given server accessible over internet. We don't ask you for any login or password, this service only returns information available during SSH handshake - notably supported encryption and MAC algorithms, and an overview of offered server public keys.

1. Open your sshd_config file using your favorite text editor.
2. Test configuration file syntax using sshd.

   Use -f option to test alternate configuration file.

3. Fix your sshd_config file for errors and continue testing.
4. Restart SSHd service for the changes to take effect.

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This topic covers the Windows-specific configuration for OpenSSH Server (sshd).

Check Ssh Server Status Ubuntu

OpenSSH maintains detailed documentation for configuration options online at OpenSSH.com, which is not duplicated in this documentation set.

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.

Check Ssh Server Status

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 username@host 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

AuthenticationMethods

For Windows OpenSSH, the only available authentication methods are 'password' and 'publickey'.

AuthorizedKeysFile

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.

ChrootDirectory (Support added in v7.7.0.0)

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.

HostKey

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.

Match

Note that pattern rules in this section. User and group names should be in lower case.

PermitRootLogin

Not applicable in Windows. To prevent administrator login, use Administrators with DenyGroups directive.

SyslogFacility

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.

Not supported

The following configuration options are not available in the OpenSSH version that ships in Windows Server 2019 and Windows 10 1809:

• AcceptEnv
• AllowStreamLocalForwarding
• AuthorizedKeysCommand
• AuthorizedKeysCommandUser
• AuthorizedPrincipalsCommand
• AuthorizedPrincipalsCommandUser
• Compression
• ExposeAuthInfo
• GSSAPIAuthentication
• GSSAPICleanupCredentials
• GSSAPIStrictAcceptorCheck
• HostbasedAcceptedKeyTypes
• HostbasedAuthentication
• HostbasedUsesNameFromPacketOnly
• IgnoreRhosts
• IgnoreUserKnownHosts
• KbdInteractiveAuthentication
• KerberosAuthentication
• KerberosGetAFSToken
• KerberosOrLocalPasswd
• KerberosTicketCleanup
• PermitTunnel
• PermitUserEnvironment
• PermitUserRC
• PidFile
• PrintLastLog
• RDomain
• StreamLocalBindMask
• StreamLocalBindUnlink
• StrictModes
• X11DisplayOffset
• X11Forwarding
• X11UseLocalhost
• XAuthLocation