Elastic Compute Service:Issues that occur when VNC or Workbench is used to connect to an instance

Problem description

When you use Workbench to connect to a Linux instance, an error message similar to the following one appears: Failed to log on to i-m5e****73a (47.*.*.157:3389) because the connection timed out.

Possible causes

• The security group rules of the Linux instance deny Workbench connections.

• Port 22 is not the default port used by the SSH process.

• The firewall settings of the Linux instance deny Workbench connections.

Solution

1. Check the SSH port of the Linux instance. For more information, see Configure the corresponding security group policy after enabling the SSH service for Linux instances.

   • The port is not port 22.

     Change the SSH port to port 22 and then use Workbench to connect to the new port of the instance.

   • The port is port 22.

     Proceed to the next step.

2. Check the security group settings of the Linux instance to determine whether the SSH port is open. For more information, see View security group rules.

   Note

   • In this example, port 22 is used. Port 22 is the default port for SSH. If you have changed the default SSH port, you must use the new default port.

   • If the authorization object is not 0.0.0.0/0, you must specify the IP addresses of the instance that you want to access as the authorization objects. In this example, 47.96.60.0/24 and 118.31.243.0/24 are used.

   Rule direction	Action	Priority	Port range	Authorization object
   Inbound	Allow	1	Destination: 22/22	Source: 47.96.60.0/24 and 118.31.243.0/24 Source: 0.0.0.0/0

   • The SSH port is not open.

     Add a security group rule based on the preceding table to a security group of the instance to allow Workbench connections to the port. For more information, see Connect to a Linux instance by using a password or key.

   • The SSH port is open.

     Proceed to the next step.

3. Check whether the firewall service is enabled for the Linux instance to deny Workbench connections to the SSH port.

   1. Connect to the Linux instance by using Virtual Network Computing (VNC). For more information, see Connect to an instance by using VNC.

   2. Check the status of the firewall.

      • If the firewall is enabled, disable the firewall and use Workbench to connect to the instance.

      • If the firewall is disabled, proceed to the next step.

   3. If you still cannot use Workbench to connect to the instance, we recommend that you use VNC to connect to the instance.

Problem description

When you use Workbench to connect to a Linux instance, the following error message appears: DefaultConnectFuture[root@/xxx.xxx.xx.xxx:22]: Failed (AnnotatedConnectException) to execyte: Connection refused: /xxx.xxx.xx.xxx:22.

Possible causes

The SSH or Remote Desktop Connection (RDP) service is not enabled on the Linux instance.

Solution

• Check whether the SSH or RDP service is enabled on the Linux instance. If not, enable the SSH or RDP service based on your business requirements.

• Check whether the Linux instance has the required port open. If not, open the port. For SSH connections, open port 22. For RDP connections, open port 3389.

Problem description

When you use Workbench to connect to a Linux instance, an error message similar to the following one appears: Failed to log on to the instance because the username or password is incorrect.

Possible causes

• An incorrect username or password is used.

• The SSH settings of the Linux instance do not allow logons of the root user.

Solution

1. If the username and password you entered are incorrect, reset the password of the instance. For more information, see Reset the logon password of an instance.

2. If the username and password you entered are correct, the SSH settings of the Linux instance may not allow logons of the root user. Use one of the following methods to resolve the issue:

   • Connect to the instance as a non-root user.

   • Connect to the instance by using VNC as the root user.

     For information about how to use VNC, see Connect to an instance by using VNC.

     Note

     For information about how to connect to an instance as the root user over SSH, see Connect to a Linux instance by using a password or key.

Problem description

When you use Workbench to connect to a Windows instance, an error message similar to the following one appears: Failed to log on to i-m5e****73a (47.*.*.157:3389) because the connection timed out.

Possible causes

• The security group settings of the Windows instance deny Workbench connections.

• RDP uses a non-3389 default port.

• The firewall settings of the Windows instance deny Workbench connections.

• Third-party security management software prevents logons of specific users.

Solution

1. Check the RDP port of the Windows instance. For more information, see How do I view and change the default port for Remote Desktop on a Windows instance?

   • The port is not port 3389.

     Change the port to port 3389 and then connect to the new port by using RDP.

   • The port is port 3389.

     Proceed to the next step.

2. Check the security group settings of the Windows instance to determine whether the RDP port is open. For more information, see View security group rules.

   Note

   • In this example, port 3389 is used. Port 3389 is the default port for RDP. If you have changed the default RDP port, use the new default port.

   • If the authorization object is not 0.0.0.0/0, you must specify the IP addresses of the instance that you want to access as the authorization objects. In this example, 47.96.60.0/24 and 118.31.243.0/24 are used.

   Rule direction	Action	Priority	Port range	Authorization object
   Inbound	Allow	1	Destination: 3389/3389	Source: 47.96.60.0/24 and 118.31.243.0/24 Source: 0.0.0.0/0

   • The RDP port is not open.

     Add a security group rule based on the preceding table to a security group of the instance to allow Workbench connections to the port. For more information, see Connect to a Windows instance by using a password or key.

   • The RDP port is open.

     Proceed to the next step.

3. Check whether the firewall service is enabled for the Windows instance to deny Workbench connections to the RDP port.

   1. Connect to the Windows instance by using VNC. For more information, see Connect to an instance by using VNC.

   2. Check the status of the firewall.

      • If the firewall is enabled, disable the firewall and use Workbench to connect to the instance.

      • If the firewall is disabled, proceed to the next step.

4. Check whether third-party security management software, such as Safedog, is installed on the Windows instance, and whether the software disables logons of specific users.

   • The third-party security management software is installed and disables logons of specific users.

     Lift this restriction and use Workbench to connect to the instance.

   • The third-party security management software is not installed, or the software is installed but enables logons of specific users.

     The Windows instance may be configured with other system settings that disable logons of specific users. We recommend that you use VNC to connect to the instance. For more information, see Connect to an instance by using VNC.

Problem description

When you use Workbench to connect to a Windows instance, an error message similar to the following one appears: Failed to log on to the instance because the username or password is incorrect.

Possible causes

• An incorrect username or password is used.

• The user that you use is not a member of the Remote Desktop Users group.

• The local security policy of the Windows instance disables logons of specific users.

Solution

1. Check whether the username that you entered is Administrator.

   • The username is not Administrator.

     The default username of RDP is Administrator in Windows. If you did not reset the default username, use Administrator to connect to the instance.

   • The username is Administrator.

     Proceed to the next step.

2. Check whether you entered the correct username and password in Workbench.

   • The username or password is incorrect.

     If you manually enter the username and password, typos may exist. Check the entered username and password.

     Note

     The misspelling of Administrator is one of the most common reasons that cause connection failures.

   • You forget the password.

     Reset the password and then use the new password to connect to the instance. For more information, see Reset the logon password of an instance.

   • The username and password are correct.

     Proceed to the next step.

3. If you have modified the local security policy of the Windows instance, check whether the local security policy disables logons of specific users. For more information, see the "Solution 1: Modify the local security policy" section in What do I do if the error message that indicates lack of Terminal Server User Access permissions appears when I connect to a Windows instance by using Remote Desktop?

   Note

   Connect to the Windows instance by using VNC and then check the local security policy of the instance. For more information, see Connect to an instance by using VNC.

   • The local security policy disables logons of the user that you use.

     Remove the user from the local security policy and use the user to connect to the instance.

   • The local security policy is not changed, or the local security policy does not disable logons of users.

     Proceed to the next step.

4. If you use a non-administrator user to connect to the instance, check whether the user is a member of the Remote Desktop Users group. For more information, see the "Solution 2: Grant the logon permissions to general users" section in What do I do if the error message that indicates lack of Terminal Server User Access permissions appears when I connect to a Windows instance by using Remote Desktop?

   • The user is not a member of the Remote Desktop Users group.

     Add the user to the group and connect to the instance as the user.

   • The user is a member of the Remote Desktop Users group.

     The Windows instance may be configured with other system settings that disable logons of specific users. We recommend that you use VNC to connect to the instance. For more information, see Connect to an instance by using VNC.

A black screen indicates that the instance is in sleep mode. Perform the following operations based on your operating system:

• For a Linux instance, click your mouse or press any key to activate the instance and go to the logon page.

• For a Windows instance, choose Send Remote Commands > CTRL+ALT+DELETE to go to the logon page.

You can use a browser to access the VNC management terminal for troubleshooting. For example, you can use Google Chrome to access the VNC management terminal, and press the F12 key to open the developer tools panel. Then, click the Console tab and identify errors based on the information displayed.

VNC management terminals support Internet Explorer 10 and later.

We recommend that you use Google Chrome because it is most compatible with the Alibaba Cloud Management Console.

This issue occurs if the encryption algorithm used by your version of Firefox is different from that used by the VNC management terminal.

We recommend that you use Google Chrome because it is most compatible with the Alibaba Cloud Management Console.

If two cursors appear when you use a VNC management terminal to connect to a Windows instance of the g7, c7, or r7 instance family, perform the following operations to modify mouse settings:

1. Modify mouse settings in Control Panel.

   1. Open Control Panel, set View by to Small icons. Then, click Mouse.

   2. In the Mouse Properties dialog box, click the Pointer Options tab, clear Enhance pointer precision, and then click OK.

2. Modify mouse settings in the registry.

   Note

   If two cursors do not appear in the user logon window, skip this step.

   1. Open Registry Editor.

   2. In the left-side hierarchy tree, click HKEY_USERS and choose Edit > Find in the top navigation bar.

   3. In the Find dialog box, enter MouseSpeed and click Find Next.

   4. Double-click MouseSpeed. In the Edit String dialog box, set Valid data to 0 and click OK.

3. Use a VNC management terminal to connect to the Windows instance again.