For SSL, does each domain name require a dedicated IP address?

kahanu

I have a wildcard SSL cert as *.mydomain.com and it will be used on a Windows Server 2012 with IIS 8.0.  My domains are as follows:

• https://www.mydomain.com
• https://dashboard.mydomain.com
• https://another.mydomain.com

My question is, do each of these domains require a separate dedicated IP address or can they all use the same IP address?  I'm getting conflicting opinions on this and I want to find out what is actually correct.

Any help is appreciated.

Thanks.

LGarvin

In general, there are three methodologies you can use to implement multiple websites on an IIS server:

In all three cases, it requires you to place each website in a separate virtual root.

• Distinction by IP Address - configure a unique IP Address for each virtual root. All IP Addresses must be configured as logical IP Addresses on one of the NICs installed.
• Distinction by Host Header (e.g. the URL of the website) - configure the Host Header in the virtual root bindings. Only requests sent to that URL will be answered by that virtual root, and only one IP Address is required on the server. This is the most common methodology for implementing multiple web sites on a single server.
• Distinction by Port Listener - this method is rarely used, although is employed by WSUS, for example. Typically the Default Web Site listens on port 80, and alternate virtual roots are configured to listen on a different port (e.g. for WSUS, the "WSUS Administration" website listens on port 8530). This methodology is not recommended for user-interactive websites because it requires the end-user to suffix the URL with the correct port number (which also requires the end-user to know the correct port number).