Logging into Linux Instance via SSH Key

Scenario

This document introduces how to use SSH key to log into a Linux instance in a local computer using Linux or MacOS.

Applicable Local OS

Linux or Mac OS

Authentication Method

Password or SSH Key

Prerequisites

• You must already have the admin account/password (or key) for the instance to be logged in to.
  • If you use a system default password to log in to the instance, first go to Internal Message to get it.
  • If you log in to the instance with a key, you must have created a key and bound the key to this CVM. For more information, see SSH Keys.
  • If you forget your password, then reset the instance password.
• A public IP has been purchased for your CVM instance, and port 22 is open (this is open by default for CVMs purchased with quick configuration).

Steps

Logging in with a Password

1. Execute the following command to connect to the Linux CVM.

   If your local computer uses Mac OS, you must open the system’s provided terminal, and then execute the following command.
   If your local computer uses Linux, you can directly execute the following command.

   ssh <username>@<hostname or IP address>

   • username is the default account name obtained as a prerequisite.
   • hostname or IP address is the public IP address or custom domain name of your Linux instance.
2. Enter the password you have already obtained, and press Enter to log in.

Logging in with a Key

1. Execute the following command to set the private key file to readable only to you.

   If your local computer uses Mac OS, you must open the system’s provided terminal, and then execute the following command.
   If your local computer uses Linux, you can directly execute the following command.

   chmod 400 <The absolute path of the private key downloaded to be associated with the CVM>

2. Execute the following command to perform remote log in.

   ssh -i <The absolute path of the private key downloaded to be associated with the CVM> <username>@<hostname or IP address>

   • username is the default account name obtained as a prerequisite.
   • hostname or IP address is the public IP address or custom domain name of your Linux instance.

   For example, execute the ssh -i "Mac/Downloads/shawn_qcloud_stable" ubuntu@192.168.11.123 command to remotely log into the Linux CVM.