Apache virtual hosts: Can clients figure out which other sites I am hosting?

Self-Hosting
1

Suppose I have a single VPS running on one of the major clouds and it’s using Apache virtual hosts to serve three websites over three different domains: example1.com, example2.com, example3.com.

Can someone who is browsing example1.com think, Hmm, I wonder what other sites this person runs? and figure out that example2.com and example3.com are coming from the same server?

I think the answer is yes because they have the same IP address and thus it’s just a reverse DNS lookup, right?

Is there anything I can do to prevent this?

2

To my knowledge the only way to prevent this is to have another host machine to point your domain to and have it forward traffic back to the real site.

3

Thanks. At that point I think it would be more cost effective to just run separate hosts for each site.

4

I think you can block people from finding this info out if your domains are behind Cloudflare’s proxy as it hides all your domain’s info.