несколько SSL сертификатов на 1 IP

Ключевое слово - SNI

Тонкость: XP+IE в пролёте.


Browsers with support for TLS server name indication[5]
Internet Explorer 7 or later, on Windows Vista or higher. Does not work on Windows XP, even Internet Explorer 8.
Mozilla Firefox 2.0 or later
Opera 8.0 or later (the TLS 1.1 protocol must be enabled)
Opera Mobile at least version 10.1 beta on Android[citation needed]
Google Chrome (Vista or higher. XP on Chrome 6 or newer.[6] OS X 10.5.7 or higher on Chrome 5.0.342.1 or newer)
Safari 2.1 or later (Mac OS X 10.5.6 or higher and Windows Vista or higher)
Konqueror/KDE 4.7 or later [7]
MobileSafari in Apple iOS 4.0 or later[8]
Android default browser on Honeycomb (v3.x) or newer[9]
Windows Phone 7[citation needed]
MicroB on Maemo



Servers
Apache 2.2.12 or later using mod_ssl[10][11][12] (or alternatively with experimental mod_gnutls[13])
Apache Traffic Server 3.2.0 or later.
Versions of lighttpd 1.4.x and 1.5.x with patch,[14] or 1.4.24+ without patch[15]
Nginx with an accompanying OpenSSL built with SNI support