ACP-Cloud1 Exam Dumps : ACP Cloud Computing Certification

RDS provides whitelist access policies. You can set permitted IP addresses and IP network segments to effectively prevent hackers from attacking the server by port scanning1. A whitelist is a list of IP addresses or CIDR blocks that are allowed to access an RDS instance. By default, the whitelist is empty, which means that no IP address can access the RDS instance. You can add IP addresses or CIDR blocks to the whitelist to allow access from specific sources. You can also modify or delete the whitelist as needed2. Whitelist access policies help improve the security of your RDS instance and protect your data from unauthorized access3. 

When using Alibaba Cloud SLB to forward layer 7 (HTTP) service requests, SLB will replace the IP address in the HTTP header file to forward requests. Therefore, the source IP address that can be seen on the backend ECS instance is the IP address of SLB instead of the client’s real IP address. However, SLB also provides a feature called X-Forwarded-For (XFF) that can help you obtain the real IP address of the client. XFF is a standard HTTP header field that records the original IP address of the client and the proxy servers that the request passes through. You can enable XFF on the SLB console or by using the API, and then configure your backend ECS instance to parse the XFF header field and get the real IP address of the client. References: 1 - SLB overview - Alibaba Cloud Document Center - Layer 7 listeners - X-Forwarded-For

The ossbrowser is a graphical tool provided by Alibaba Cloud for uploading and downloading files in OSS, offering an intuitive interface for managing objects. Other tools like ossutil and osscmd are command-line tools, while ossfs is used to mount OSS as a file system on Linux, not a graphical tool.