#1 Global Leader in Data Resilience

Backup Job to AWS S3 Repository Fails with "Failed to construct ClientAgentProtocol"

KB ID: 4490
Product: Veeam Backup & Replication | 11 | 12
Published: 2023-08-29
Last Modified: 2023-08-29
mailbox
Get weekly article updates
By subscribing, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.

Cheers for trusting us with the spot in your mailbox!

Now you’re less likely to miss what’s been brewing in our knowledge base with this weekly digest

error icon

Oops! Something went wrong.

Please, try again later.

Challenge

While attempting to execute a backup task within Veeam Backup & Replication directed towards an AWS S3 Bucket Repository, the backup process fails with the error:

Failed to construct ClientAgentProtocol.
error

Examining the logs reveals the following errors:

In log: job.[IP].BlobRepo.log

ERR |Veeam RPC client processor thread is broken
>>  |Failed to do TLS handshake. Possible cause: Incompatible SSL version: available - TLSv1.2, negotiated - TLSv1.1, detailed info: Failed to do TLS handshake: (336109835) error:1408A10B:SSL routines:ssl3_get_client_hello:wrong version number
>>  |--tr:Failed to perform TLS handshake
>>  |An exception was thrown from thread [8972]. 

Cause

This error occurs when the machine initiating communication with the AWS endpoint is unable to complete the TLS handshake due to an inability to use TLS 1.2.

Due to multiple security vulnerabilities, many companies, including AWS, have deprecated TLS 1.0 and TLS 1.1.
AWS Security Blog - TLS 1.2 to become the minimum TLS protocol level for all AWS API endpoints

Solution

To resolve this, ensure that the OS of the machines used by Veeam Backup & Replication to communicate with the AWS endpoint can use at least TLS 1.2.

TLS 1.2 is enabled by default is all Windows operating systems, starting with Windows 8.1/Server 2012 R2.

More Information

Note: Veeam Backup & Replication 11/12 uses .NET Framework 4.7.2, which supports at most TLS 1.2.

Veeam Backup & Replication System Requirements

To submit feedback regarding this article, please click this link: Send Article Feedback
To report a typo on this page, highlight the typo with your mouse and press CTRL + Enter.

Spelling error in text

This site is protected by hCaptcha and its Privacy Policy and Terms of Service apply except as noted in our Privacy Policy.
Thank you!

Thank you!

Your feedback has been received and will be reviewed.

Oops! Something went wrong.

Please, try again later.

You have selected too large block!

Please try select less.

KB Feedback/Suggestion

This form is only for KB Feedback/Suggestions, if you need help with the software open a support case

By submitting, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.
This site is protected by hCaptcha and its Privacy Policy and Terms of Service apply except as noted in our Privacy Policy.
Verify your email to continue your product download
We've sent a verification code to:
  • Incorrect verification code. Please try again.
An email with a verification code was just sent to
Didn't receive the code? Click to resend in sec
Didn't receive the code? Click to resend
Thank you!

Thank you!

Your feedback has been received and will be reviewed.

error icon

Oops! Something went wrong.

Please, try again later.