An administrator changed the SFTP server used for scheduled NSX Manager backups. The backup jobs now fail with the error "Host KEY Verification Failed." The connectivity and credentials are correct…

Question

Options

• ATurn Off Backup encryption.
• BUpdate the SSH fingerprint.
• CTrust the certificate on the SFTP server.
• DUse the NSX cluster VIP as the SFTP endpoint.

• A
  16% (9)
• B
  71% (39)
• C
  9% (5)
• D
  4% (2)

Explanation

In VMware Cloud Foundation (VCF), the NSX Manager uses the SFTP protocol to securely transfer configuration backups to an external repository. SFTP is built on top of the SSH protocol, which relies on a "Trust on First Use" (TOFU) model for verifying the identity of the remote host. When an NSX Manager first connects to an SFTP server, it retrieves the server's SSH Public Key Fingerprint and stores it in its local known_hosts equivalent database. This fingerprint ensures that future connections are made to the same, verified server, preventing man-in-the-middle The error "Host KEY Verification Failed" occurs when the administrator changes the SFTP server (or if the SFTP server's OS was reinstalled/keys regenerated). Even if the IP address remains the same, the new server presents a different SSH fingerprint than the one currently cached in the NSX Manager configuration. Because the signatures do not match, the NSX Manager aborts the connection for security reasons. To resolve this issue, the administrator must Update the SSH fingerprint (Option B) within the NSX Manager backup settings. This involves: Retrieving the new fingerprint from the SFTP server (e.g., via ssh- Navigating to System > Lifecycle > Backup & Restore in the NSX Editing the File Server configuration and pasting the new fingerprint into the appropriate field.

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