1) On your Teradata Database image and on your viewpoint image in addition to the default ports that are opened make sure you open ports 5180, 5190, 22, and 1025 in your security group to the private IP address of your Server Management Image and click "Save".
So for example if My private IP address for server management is 172.31.30.22, then I add that IP address with a /32 at the end to look like this: 172.31.30.22/32
2) Connect to your Server Management (CMIC) system using the public IP address from your PC or other system that has your private key on it. In your ssh software (SecureCRT or Open SSH) make sure you are doing the following:
a) Specify cmic (instead of root or ec2-user) as the username.
b) Make sure you are using a 256 bit key exchange protocol such as "diffie-hellman-group-exchange-sha256. The key exchage protocol is different on the CMIC than the Teradata nodes and requires a higher level of security. Make sure that you have selected the following Ciphers: AEC-256-CTR, AEC-192-CTR, AES-128-CTR
c) Make sure you have specified the your private key that you started your image with. There is no password set for the CMIC, instead your private key is required. The private key is the file that ends with ".pem" in the name.