When hosting multiple sites on a single IP, HTTP1.1 has the necessary items on board to route the request to the correct site. This works because an HTTP 1.1 request includes a Host: header, which indicates to the server which site the client wishes to access.
When using SSL-secured connections, this doesn’t work anymore. The problem is similar to the situation in HTTP1.0: The server needs to know to which SSL-host the connection is addressed. SNI introduces a similar solution: It specifies an extension to the SSL negotiation to indicate which server the client wishes to access.
