Hi everyone
I'm experiencing an issue with one of our Veeam backup jobs where the process fails consistently with the following error:
Error: Failed to do TLS handshake.
Possible cause: Unknown error
Detailed info: Reconnectable protocol device was closed.
Context:
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Veeam Backup & Replication is being used for a daily VM backup job.
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The failure occurs for a single VM.
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The backup job retries multiple times, but ends with 0 bytes transferred and a final error after approximately 2 minutes.
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TLS handshake failure seems to prevent the backup from initializing.
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No successful backup was performed (0 B read, 0 B transferred).
What we’ve tried so far:
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Verified basic network connectivity.
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Restarted both the Veeam Backup server and the affected VM.
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Confirmed that the VM is reachable and responsive.
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No recent configuration changes were made to the VM or the infrastructure.
Questions:
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What could be causing the TLS handshake to fail in this context?
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Could this be related to certificate issues or an outdated Veeam transport service?
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Are there specific logs I should collect for deeper troubleshooting?
Any help or guidance would be greatly appreciated!
Thanks in advance!

