Question
Why it is not possible to establish SSL connection to IP address if a default website is assigned on Plesk for Windows, whereas on Plesk for Linux such a behavior is possible.
Answer
IP:Port
SSL binding has higher priority than Hostname:Port
SSL binding.
For example, configure two websites with SSL:
-
sni.example.com
with SNI (Hostname:Port) SSL binding*:443:sni.example.com
and certificatecert_sni
which resolves to203.0.113.2
IP address -
non-sni.example.com
with legacy (IP:Port) SSL binding 203.0.113.1:443:* and certificatecert_non_sni
On accessing to https://sni.example.com
– the certificate cert_non_sni
 will be provided by the IIS instead of cert_sni
.
That is why Plesk does not create legacy (IP:Port) SSL binding on websites.
Additional information
Microsoft Blog: Server Name Indication (SNI) with IIS 8 (Windows Server 2012)