Which algorithms are you trying to use instead? what is security ssh show for that cluster shows?
The SSH protocol uses a Diffie-Hellman based key exchange method to establish a shared secret key during the SSH negotiation phrase. The key exchange method specifies how one-time session keys are generated for encryption and authentication and how the server authentication takes place. Data ONTAP supports the diffie-hellman-group-exchange-sha256 key exchange algorithm for SHA-2. Data ONTAP also supports the diffie-hellman-group-exchange-sha1, diffie-hellman-group14-sha1, and diffie-hellman-group1-sha1 key exchange algorithms for SHA-1. Data ONTAP also supports ecdh-sha2-nistp256, ecdh-sha2-nistp384, ecdh-sha2-nistp521, curve25519-sha256. Data ONTAP also supports the AES and 3DES symmetric encryptions (also known as ciphers) of the following types: aes256-ctr, aes192-ctr, aes128-ctr, aes256-cbc, aes192-cbc, aes128-cbc, aes128-gcm, aes256-gcm and 3des-cbc. Data ONTAP supports MAC algorithms of the following types: hmac-sha1, hmac-sha1-96, hmac-md5, hmac-md5-96, hmac-ripemd160, umac-64, umac-64, umac-128, hmac-sha2-256, hmac-sha2-512, hmac-sha1-etm, hmac-sha1-96-etm, hmac-sha2-256-etm, hmac-sha2-512-etm, hmac-md5-etm, hmac-md5-96-etm, hmac-ripemd160-etm, umac-64-etm, umac-128-etm
i have discovered the same issue. Also using PSTK 9.8.0 and Powershell 5.1.xx Desktop Edition, on a (unsecure) system with all MAC-algorithm enabled, the "invoke-ncssh" command runs fine, on a secured system with only the four algorithms enabled like Elfeuro described, the command does not run.
Is there a way to tell powershell to use an alternative MAC-algorithm? For instance a global variable or a parameter for a cmdlet?