When attempting to add a managed Linux server or edit a Linux repository one of the following errors occurs:
Negotiation failed. The client and the server have no common key exchange algorithm.
Negotiation failed. The client and the server have no common encryption algorithm.
Failed to negotiate key exchange algorithm
Client encryption algorithm not found
Server HMAC algorithm not found
These errors occur when the Linux server is not configured to allow a Cipher, Key Exchange Algorithm, and MAC Algorithm compatible with the SSH libraries used by Veeam Backup & Replication.
Starting with Veeam Backup & Replication 11, an additional SSH library is used, allowing for an expanded list of supported Ciphers, Key Exchange Algorithms, and MAC Algorithms. Therefore, it is highly recommended to use the latest version of Veeam Backup & Replication to ensure maximum compatibility.
To resolve this connection issue, ensure that the Linux server's sshd is able to use Ciphers, Key Exchange Algorithms, and MAC Algorithms that are compatible with Veeam Backup & Replication.