The authenticity of host 'ecs-030403-0002 (192.168.0.154)' can't be established.

This message indicates that the SSH client is connecting to a remote host for the first time and does not have the host key fingerprint stored in its known_hosts file.

To resolve this issue, you can verify the authenticity of the host by comparing the host key fingerprint provided by the SSH server to the one stored in your known_hosts file. If they match, you can proceed with connecting to the remote host.

Alternatively, you can add the host key fingerprint to your known_hosts file by accepting the prompt to do so when connecting to the remote host for the first time. This will prevent future warnings about the authenticity of the host.