Preventing DDoS on a Discourse instance?

[HAWK]

There are a few more recent topics that cover this.

How to protect a server's IP from being exposed?

My forum has CloudFlare and when inserting a URL from this service, I can get the real IP of my server, this is a big gift for DDoS attacks. I checked it on the Discourse Meta and this forum don’t have URL-filtration too. [1] [2] Blocked domain by IPlogger can’t help because the attacker can use a custom domain using the script for logger ip address. I think need use whitelist to filter domain who can use onebox. Example: if admin allow only url from Youtube, Twitter, Imgur, all other ur…