Hi,
we hardening our SSH Servers, but after that, RDM Login failed.
testing/hardening:
https://www.sshaudit.com/
https://www.sshaudit.com/hardening_guides.html#ubuntu_18_04_lts
Our SSH Settings:
KexAlgorithms diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,curve25519-sha256@libssh.org,diffie-hellman-group16-sha512
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
MACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com
Login is possible with putty > 0.63, also Mobaxterm ~ V9
Regards
Sebastian