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 2022-11-30 GMT+08:00

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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 SMS gateway of the CBH system is a built-in gateway, and the number of messages that can be sent within a specific time has reached the maximum limit.
Cause 3: The security group denies the IP address of the SMS gateway, or ports 10743 and 443 are not enabled.
Cause 4: The mobile number is incorrect.
Cause 5: The SMS service is abnormal.
Cause 6: 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
1. The limitations for sending SMS verification codes are as follows and you can send the SMS verification code again based on the limitations:
  - You can send a maximum of one SMS message within 1 minute.
  - You can send a maximum of five SMS messages within an hour.
  - You can send a maximum of 15 SMS messages within 24 hours.
2. Modify the SMS gateway configuration to set it to a third-party SMS gateway.
Solution to cause 3
Configure the CBH instance security group to allow access to the SMS gateway IP address and enable ports 10743 and 443.
Solution to cause 4
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 5
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 6
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.