Connection methods

You can use a variety of methods to connect to an Elastic Compute Service (ECS) instance,such as Virtual Network Computing (VNC) and third-party client tools. Choose a method to connect to your instance based on the operating system of your instance, the operating system of your device, and the operations that you want to perform.


Operating system of your instance	Operating system of your device	Connection method
Linux	Windows	VNC For more information, see Connect to a Linux instance by using password authentication. Client tools such as PuTTY For information about how to connect to an instance by using an SSH key pair as the credential, see Use an SSH key pair to connect to a Linux instance from a Windows device. For information about how to connect to an instance by using a username and password as the credential, see Use a username and password to connect to a Linux instance from a Windows device.
	UNIX-like operating systems such as Linux and macOS	VNC For more information, see Connect to a Linux instance by using password authentication. SSH commands For information about how to connect to an instance by using an SSH key pair as the credential, see Use an SSH key pair to connect to a Linux instance from a device that supports SSH commands (configure information by using commands). For information about how to connect to an instance by using a username and password as the credential, see Use a username and password to connect to a Linux instance from a Linux or Mac OS X device.
	Operating systems of mobile devices, such as iOS and Android	Apps such as SSH Control Lite and JuiceSSH For more information, see Connect to a Linux instance from a mobile device.
Windows	Windows	VNC For more information, see Connect to a Windows instance by using password authentication. Client tools such as Remote Desktop Connection (formerly called MSTSC) For more information, see Connect from a local client that runs a Windows operating system.
	Linux	VNC For more information, see Connect to a Windows instance by using password authentication. Client tools such as rdesktop For more information, see Connect from a local client that runs a Linux operating system.
	macOS	VNC For more information, see Connect to a Windows instance by using password authentication. Client tools such as Microsoft Remote Desktop Connection for Mac For more information, see Get started with the macOS client.
	Operating systems of mobile devices, such as iOS and Android	Apps such as Microsoft Remote Desktop For more information, see Connect to a Windows instance from a mobile device.

Note

Except for VNC, all other connection tools require that instances have public IP addresses or elastic IP addresses (EIPs) assigned.
After a Windows instance is created, it takes 2 to 3 minutes to initialize the operating system. Do not restart the instance while it is being initialized. After a non-I/O optimized Windows instance is created, it takes 10 minutes to initialize the operating system. Do not connect to the instance while it is being initialized.

Comparison of connection tools

The following table describes the advantages of VNC and other third-party client tools.


Item	VNC	Third-party client tool
Assignment of a public IP address or an EIP to the instance	Optional. VNC can be used to troubleshoot network configuration exceptions, such as firewalls being enabled by mistake.	Required.
Enabling services such as SSH on the instance	Optional. VNC can be used to troubleshoot SSH service exceptions, such as SSHD being disabled.	Required.
Logons by using the ECS console	Supported.	Not supported. The local client must be installed.
Independence of the instance operating system	VNC can be used to connect to both Linux and Windows instances.	Depends on the client tool. The third-party client tools can be used to connect to Linux or Windows instances.
Simultaneous logons by multiple operating system users to a single instance	Not supported.	Depends on the client tool.
Ease of interaction	VNC does not allow you to copy or paste text. To copy or paste text, use the feature for copying long commands.	Depends on the client tool.
Visually viewing Linux system file resources	Not supported.	Depends on the client tool.
Permissions to control and modify hardware	Supported. VNC can be used to manage resources such as BIOS and troubleshoot exceptions such as system startup failures.	Not supported.
Terminal configurability	Not supported.	Supported, but detailed capabilities vary based on the client tool.