vi /var/log/message
Jul 2 16:03:07 xxx sshd[3087]: Unable to negotiate with xxx.xxx.xxx.xxx port 40568: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 [preauth]
Jul 2 16:10:46 xxx sshd[3245]: Unable to negotiate with xxx.xxx.xxx.xxx port 41172: no matching MAC found. Their offer: hmac-sha1-96,hmac-sha1,hmac-md5-96,hmac-md5 [preauth]
vi /etc/ssh/sshd_config
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,hmac-sha1-96,hmac-sha1,hmac-md5-96,hmac-md5
KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1