Why would a corporate web server be assigned a public IP address instead of a private IP address?

Answer 1

Because the systems administrator does not understand how to properly zone his network, or it is supposed to be exposed directly.

Actually, without a public IP address, no one outside the local network of that business could see it, which kind of defeats the purpose of having a website (many businesses do have internal web servers for employees only, but these are in addition to the public website).

There's really no reason the public web server can't have both a public and a private IP address, and in fact this is a fairly common setup.

____________________________________________________________________

I beg to differ, you never want to directly expose your machine to the public internet, you want it to have data passing through a gateway preferably a firewall, and requests to be forwarded correctly.

E.G.:

Gateway(domain.com Public: 66.11.11.11, Private: 10.0.0.1) Port 80-> www.domain.local [10.0.0.5]) Requests on port 80 for 66.11.11.11 will access the machine at 10.0.0.5 but the machine itself will not be exposed to the internet at large, except for the web server component itself. It is a MAJOR security risk if www.domain.com was actually at 66.11.11.11 and not behind some kind of physical gateway/firewall hence the zoning your network properly statement.