You can follow the steps for a single server written in here for example https://techcommunity.microsoft.com/t5/iis-support-blog/connection-string-encryption-and-decryption/ba-p/830094
(documentation of the ASPNET tool used in the article: https://docs.microsoft.com/en-us/previous-versions/k6h9cz8h(v=vs.100))
Pros and Cons of this are mainly these:
Pros
- Web.Config sensitive information is not in a readable condition (after encryption)
- You don't have to explicitly write code to decrypt the Web.Config file as ASP.NET automatically decrypts the configuration and processes your request
Cons
- You can't modify the encrypted content on the fly. It requires you to decrypt the content before editing.