ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 123.123.123.123
#Add below lines in /etc/ssh/ssh_config Ciphers aes256-cbc,aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc KexAlgorithms +diffie-hellman-group1-sha1