Some attackers may record real server IP history, and the exposed IPs allow them to bypass Anti-DDoS Advanced and directly attack your real server. In this case, you are recommended to change the actual real server IP.
If you don't want to change the IP of your real server or have already done so but the IP is still exposed, in order to prevent attacker from bypassing Anti-DDoS and directly attack your real server IP, please follow the steps below:
Before changing the real server IP, be sure to confirm that all factors that may expose the IP have been eliminated.
You can refer to the following steps before changing the real server IP to check the risk factors and prevent the new IP from disclosure.
Check all the DNS resolution records of the attacked real server IP, including resolution records of sub-domain names, MX (Mail Exchanger) records of mail servers, and NS (Name Server) records. Make sure that all those records are configured for protection by Anti-DDoS Advanced, so that none of them will be resolved to the new real server IP.
Check your real server for potential trojans, backdoors, and other hidden risks.