Can parking a domain on my primary domain have an effect on primary domain's SEO?

Question

I have a primary domain (assume it is example.com).

Now I parked domain-static.example on example.com.

The idea is that static content (images, JS, CSS) is served from domain-static.example, and domain-static.example passes through a CDN which is where the difference is between the domains. The reason is that browsers limit simultaneous downloads from the same domain so I think it should speed up the site more than routing all requests through a CDN.

The static domain is actually parked on top of example.com, but all static content on the website is served through static-domain.example

There should not be a case where HTML pages are served from domain-static.example or really for anything Google downloads (except for images which it will download for Google Images)

But I am asking about the regular Google search, can example.com get penalized for some reason for parking domain-static.example on example.com?

If this is so, one possibility I thought of is adding a .htaccess rule that does not let any dynamic content be served from the static domain, so there is not a possibility of Google downloading dynamic content from the domain-static.example, which can eliminate dynamic content.

What do you think I should do?

Answer 1

I'm not sure you understood me, I don't want the parked domain (i.e www.domain-static.com) to show up in Google Search Results, (possibly in Google Images, but I don't really care about that).

Then put the noindex/nofollow tag on your site

Answer 2

It's ok to park one domain on another as long as the domain doesn't have a bad history (part of a link farm, serving malware, etc) and you can't pull up content from the main domain with the parked domains URL (duplicate content issues).

If the parked domain has a bad history it may affect the main domain if Google can associate the two as being part of the same network (they can do this by checking domain registration or seeing the both serve up the same content). So if the parked domain has a bad reputation I wouldn't park in on top of the main domain.

If you do choose to park it on the main domain make sure you do a 301 redirect from the parked domain to the main domain. That way you prevent content from being available with multiple URLs.

If you do park it on the main domain make sure you change it to be a basic landing page about 90 days before you launch as Google may have issues picking up the new site (source)