What is the point of having more than a single public IP address for a dedicated server with a single network interface? I see a lot of dedicated server hosting offers that show something like "public IPs: 8". What am I missing? Thanks!
One reason is to provision multiple SSL encrypted services on the same port. SSL starts before the application layer which leads to certificate errors when accessing the host on a hostname that doesn't match the CN value on the certificate.
Using HTTP virtual hosting as an example:
The SSL layer sits between the client and the webserver. Once the client has issued the GET request (and hence transmitted the hostname it was expecting) the server has already started SSL. At that point its too late to specify a different certificate.
If you implement IP-based virtual hosting then each hostname can have it's own IP and subsequently its own certificate. Of course, wildcard certificates are another way around the problem, but they're often more expensive than just allocating another ip.