Elastic Compute Service:VNC connection issues

What are the default username and password used to connect to the operating system of an ECS instance?

The default username varies based on the operating system type of the Elastic Compute Service (ECS) instance.

• For Windows instances, the default username is Administrator.

• For Linux instances, the default username is root or ecs-user.

The password used to connect to the operating system of an instance is set during instance creation. For more information, see Create an instance on the Custom Launch tab. If you forget the logon password or want to change it after instance creation, you can reset it online. For more information, see Reset the logon password of an instance.

What do I do if I cannot use the password of an ECS instance to log on to the instance by using VNC?

If you cannot connect to an ECS instance by using Virtual Network Computing (VNC) after you provide the password of the instance, perform the following steps to resolve the issue:

1. Check whether the logon password is correct.

   • Check whether the username and password that you enter are valid. For Windows instances, the default username is Administrator. For Linux instances, the default username is root or ecs-user.

   • Make sure that the password that you enter is correctly capitalized and contains no whitespaces or invalid characters.

2. Reset the logon password.

   If you forget your logon password, you can reset it in the Alibaba Cloud ECS console. For more information, see Reset the logon password of an instance.

3. Restart the ECS instance.

   You can restart the ECS instance to resolve specific temporary issues. For more information, see Restart an instance.

4. Check the VNC logon permissions.

   If you use a Resource Access Management (RAM) user to connect to the instance by using VNC, make sure that the RAM user has the required permissions. The policy in the following sample code includes the permissions to perform the ecs:DescribeInstances action, which is used to query information about ECS instances, and the ecs:DescribeInstanceVncUrl action, which is used to query the VNC connection address of an ECS instance. For more information, see Grant permissions to a RAM user.

   {
     "Version": "1",
     "Statement": [
       {
         "Effect": "Allow",
         "Action": [
           "ecs:DescribeInstances",
           "ecs:DescribeInstanceVncUrl"
         ],
         "Resource": "*"
       }
     ]
   }

5. Reconnect to the instance by using VNC.

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

Does a VNC management terminal allow multiple users to concurrently log on?

No, a VNC management terminal allows only one user to log on at a time.

What do I do if a black screen appears while I am connected to a VNC management terminal?

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.

What do I do if a VNC management terminal cannot be accessed?

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.

Why am I unable to use Internet Explorer 8.0 to access a VNC management terminal?

VNC management terminals support Internet Explorer 10 and later.

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

What do I do if an error message appears indicating that a secure connection cannot be established when I use Firefox to access a VNC management terminal?

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

We recommend that you use Google Chrome because it has the best compatibility with the Alibaba Cloud Management Console.

Why do two cursors appear after I connect to a Windows instance by using a VNC management terminal?

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 the mouse settings:

1. Modify the 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 the 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 navigation 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 Value data to 0 and click OK.

3. Reconnect to the Windows instance by using the VNC management terminal. For more information, see Connect to an instance by using VNC.