Help Center/ Cloud Bastion Host/ FAQs/ Troubleshooting/ Maintenance Issues/ Why Does SMS Verification Code Fail to Send When I Log In to a CBH Instance?
Updated on 2025-09-04 GMT+08:00
View PDF

Why Does SMS Verification Code Fail to Send When I Log In to a CBH Instance?

Symptoms

  • Mobile SMS is selected as multifactor verification for your account. When you attempt to log in to the CBH system through SMS, the system displays a message indicating that the SMS message fails to be sent.
  • After the login password is reset, you do not receive the SMS verification code.

Possible Causes

  • Cause 1: If the browser you used is incompatible with the CBH system, the login verification SMS fails to be sent.
  • Cause 2: The security group denies the IP address of the SMS gateway, or disables port 10743 and port 443.
  • Cause 3: The mobile number is incorrect.
  • Cause 4: The SMS service is abnormal.
  • Cause 5: No elastic IP address (EIP) is bound to the CBH instance.

Solutions

  • Solution to cause 1
    Use other browsers or upgrade the browser version. For details, see Table 1.
    Table 1 Recommended browsers and versions

    Browser

    Version

    Edge

    44 or later

    Google Chrome

    52.0 or later

    Safari

    10 or later

    Mozilla Firefox

    50.0 or later
  • Solution to cause 2

    Configure the CBH instance security group to allow access to the SMS gateway IP address and enable ports 10743 and 443.

  • Solution to cause 3

    If you are a system user, contact the administrator to change the mobile number bound to your account.

    If you are user admin, submit a service ticket to change the mobile number bound to your account.

  • Solution to cause 4

    Check the status of the SMS service of the bound mobile number from the following aspects:

    • Check if the mobile number is suspended due to arrears.
    • Check if the SMS message is in the spam short messages folder.
    • Check if the mobile communication network is normal.
  • Solution to cause 5

    An EIP must be bound to a CBH instance for successful logins. An EIP with a bandwidth of 5 Mbit/s or above is recommended.

Parent topic: Maintenance Issues