I have a problem with adding CSA server to my LDMS Core server when going to configure > manage CSA then adding information as the image I have this error "the ip address you supported is not vaild",, noting that my CSA doesn't have a public ip address.
also if i'm using proxy but adding its configuration or not give the same problem,, also putting the private ip address in the CSA internal ip will give the same problem .
I had this same issue, and what I had to do to resolve it was change the TLS protocol on the CSA to 1.0 (under the Gateway Service tab) and then connect from the core server. It was then successful. Then i changed TLS to 1.1 and connected from Core again and it worked. Changed it to 1.2 and connected from core and it worked that way too. Seems like it just couldn't negotiate TLS the first time and needed to be set low first to establish connection.