The limit is per _hostname_ not per _server_ (unless things have changed in the last 10 years). This is why you'll see assets1.foo.com, assets2.foo.com, etc. a

The limit is per _hostname_ not per _server_ (unless things have changed in the last 10 years). This is why you'll see assets1.foo.com, assets2.foo.com, etc. all pointing to the same IP address(es). Server-side code picks one based on a modulus of a hash of the filename or something similar when rendering the HTML to get additional pipelines in the user's browser. Not sure how or if this is done in SPA.