Updated on 2024-10-15 GMT+08:00

SMS.380x SSH Connection Failures

During a migration, an SSH connection must be established between the source server and target server. If the SSH connection cannot be established, the migration will fail. You can rectify the fault based on the error message.

SMS.3802 Failed to establish an SSH connection with the target server.

This error message is displayed when the SSH client reports the error "SSHException", indicating that an exception occurs during SSH connection setup. The possible causes and solutions are:

  • The installed SMS-Agent is not of the latest version.

    Go to the Agents page on the SMS console, download and install the latest SMS-Agent, and create a migration task again.

  • Security software or firewalls may block the connection from the source server to the target server.
    • Check the firewall settings of the source server and ensure that no outbound traffic is intercepted If the traffic is blocked, enable the involved ports and try again.
    • Check whether there is security software running on the source server. If there is, disable the security software, stop related services if necessary, and try again.

SMS.3803 The connection to the port 22 of target server failed, because an error occurred during the public key verification on the target server.

This error message is displayed when the SSH client reports error "BadHostkeyException", indicating that the public key in the known_hosts file fails to be verified. The possible causes and solutions are:

  • The connection from the source server to the target server may be blocked by security software or firewalls.
    • Check the firewall settings of the source server and ensure that no outbound traffic is block. If the traffic is blocked, enable the involved ports and try again.
    • Check whether there is security software running on the source server. If there is, disable the security software, stop related services if necessary, and try again.
  • The IP address of the target server is changed after you configure the target server in the migration task or the full migration is complete.

    The source server cannot identify the changed IP address of the target server. As a result, the authentication fails. You can delete the current task and create a new one, or change the IP address of the target server back to the original one.

  • Packet loss occurs when the target server obtains ECS metadata.

    In certain regions, such as AF-Johannesburg and AP-Jakarta, the target server may fail to obtain ECS metadata. In this case, you are advised to replace the target server and perform the migration again.

  • The migration is executed using a private network, and there is an IP address conflict between the source and target servers.

    The source server may fail to access the IP address of the target server if there is an IP address conflict between them. Check and modify the network configuration, ensure that the IP addresses do not conflict, and then try the migration again.

SMS.3804 The connection to the port 22 of target server failed due to invalid connection credential.

This error message is displayed when the SSH client reports the error "AuthenticationException" indicating that the identity authentication fails. Check whether the target server runs Windows and uses a key for login. If it does, use another cloud server as the target server and then try again. Such Windows servers cannot be used as target servers for migration.

SMS.3805 The connection to the port 22 of target server timed out.

This error message is displayed when OpenSSH reports the error "connect timeout", indicating that the SSH connection times out. As a result, the source server cannot connect to the IP address of the target server. Rectify the fault by following the instructions below.

  • Check whether the security groups, firewalls, and ACL rules allow the source server to access the target server with the IP address.

    If the access is blocked, modify the settings of the security groups, firewalls, or ACL rules to allow the access.

  • Check the network connectivity between the source and target servers. If a private network is used, check whether the source and target servers are in the same network range.

    Use SSH or Telnet to test the network connectivity between the source and target servers. If the connection fails, check the network and firewall settings.

    The commands are in the following format:

    • telnet {Target server IP address} {Port}
    • ssh {Target server IP address} {Port}
    For example, if the target server's IP address is 192.168.0.x and port 22 is used, run either of the following commands:
    telnet 192.168.0.x 22
    ssh 192.168.0.x 22
  • Check whether the target server is stopped.
    1. Log in to the management console.
    2. On the Elastic Cloud Server page, check the ECS (target server) status. If the ECS is stopped, choose More > Start in the Operation column.

SMS.3806 The connection to the port 22 of target server was rejected.

This message is displayed when OpenSSH reports the error "connect refused", which means the connection to the target server's IP address is rejected. Rectify the fault by following the instructions below.

  • Check whether the security groups, firewalls, and ACL rules allow the source server to access the target server with the IP address.

    If the access is blocked, modify the settings of the security groups, firewalls, or ACL rules to allow the access.

  • Check the network connectivity between the source and target servers. If a private network is used, check whether the source and target servers are in the same network range.

    Use SSH or Telnet to test the network connectivity between the source and target servers. If the connection fails, check the network and firewall settings.

    The commands are in the following format:

    • telnet {Target server IP address} {Port}
    • ssh {Target server IP address} {Port}
    For example, if the target server's IP address is 192.168.0.x and port 22 is used, run either of the following commands:
    telnet 192.168.0.x 22
    ssh 192.168.0.x 22