Secure Shell (SSH) 500 SSH user/group access controls. Directives are processed in the following order: deny-users, allow-users, deny-groups and allow-groups. Allow user/group SSH access Allow members of a group to login [a-z_][a-z0-9_-]{1,31}[$]? illegal characters or more than 32 characters Allow specific users to login [a-z_][a-z0-9_-]{1,31}[$]? illegal characters or more than 32 characters Deny user/group SSH access Disallow members of a group to login [a-z_][a-z0-9_-]{1,31}[$]? illegal characters or more than 32 characters Disallow specific users to login [a-z_][a-z0-9_-]{1,31}[$]? illegal characters or more than 32 characters Allowed ciphers 3des-cbc aes128-cbc aes192-cbc aes256-cbc rijndael-cbc@lysator.liu.se aes128-ctr aes192-ctr aes256-ctr aes128-gcm@openssh.com aes256-gcm@openssh.com chacha20-poly1305@openssh.com ^(3des-cbc|aes128-cbc|aes192-cbc|aes256-cbc|rijndael-cbc@lysator.liu.se|aes128-ctr|aes192-ctr|aes256-ctr|aes128-gcm@openssh.com|aes256-gcm@openssh.com|chacha20-poly1305@openssh.com)$ Disable IP Address to Hostname lookup Disable password-based authentication Allowed key exchange (KEX) algorithms diffie-hellman-group1-sha1 diffie-hellman-group14-sha1 diffie-hellman-group14-sha256 diffie-hellman-group16-sha512 diffie-hellman-group18-sha512 diffie-hellman-group-exchange-sha1 diffie-hellman-group-exchange-sha256 ecdh-sha2-nistp256 ecdh-sha2-nistp384 ecdh-sha2-nistp521 curve25519-sha256 curve25519-sha256@libssh.org ^(diffie-hellman-group1-sha1|diffie-hellman-group14-sha1|diffie-hellman-group14-sha256|diffie-hellman-group16-sha512|diffie-hellman-group18-sha512|diffie-hellman-group-exchange-sha1|diffie-hellman-group-exchange-sha256|ecdh-sha2-nistp256|ecdh-sha2-nistp384|ecdh-sha2-nistp521|curve25519-sha256|curve25519-sha256@libssh.org)$ Local addresses SSH service should listen on ipv4 IP address to listen for incoming connections ipv6 IPv6 address to listen for incoming connections Log level QUIET stay silent FATAL log fatals only ERROR log errors and fatals only INFO default log level VERBOSE enable logging of failed login attempts INFO Allowed message authentication code (MAC) algorithms hmac-sha1 hmac-sha1-96 hmac-sha2-256 hmac-sha2-512 hmac-md5 hmac-md5-96 umac-64@openssh.com umac-128@openssh.com hmac-sha1-etm@openssh.com hmac-sha1-96-etm@openssh.com hmac-sha2-256-etm@openssh.com hmac-sha2-512-etm@openssh.com hmac-md5-etm@openssh.com hmac-md5-96-etm@openssh.com umac-64-etm@openssh.com umac-128-etm@openssh.com ^(hmac-sha1|hmac-sha1-96|hmac-sha2-256|hmac-sha2-512|hmac-md5|hmac-md5-96|umac-64@openssh.com|umac-128@openssh.com|hmac-sha1-etm@openssh.com|hmac-sha1-96-etm@openssh.com|hmac-sha2-256-etm@openssh.com|hmac-sha2-512-etm@openssh.com|hmac-md5-etm@openssh.com|hmac-md5-96-etm@openssh.com|umac-64-etm@openssh.com|umac-128-etm@openssh.com)$ Port for SSH service 1-65535 Numeric IP port how often send keep alives in seconds #include