IIS SNI overview

This article applies to the following Windows® Server® versions: 2012, 2012 R2, 2016, and 2019

Server Name Identification (SNI) is an extension of the Secure Socket Layer (SSL) and Transport Layer Security (TLS) protocol. These enable you to host multiple SSL certificates on a single unique Internet Protocol (IP) address. This article provides an overview of using SNI within Internet Information Services (IIS) on a Windows® server.

Prerequisites

Your server must meet the following requirements to use SNI:

* IIS 8 or later

The following operating systems support SNI without additional modifications:

* Windows Server® 2012 or later

Configure SNI

Install the certificate by using the Install an SSL certificate article. Then return to this article to set up the bindings by using SNI.

Set up the bindings

  1. In the IIS Manager, right-click your site and select Edit Bindings.
  2. In the Site Bindings window, click Add.
  3. In the Add Site Binding dialog box, perform the following steps:
    a. Set the value of Type to https.
    b. Specify the host name.
    c. Check the box for Require Server Name Indication.
    d. From the SSL certificate list, select your certificate.
    e. Click OK.

Note: When you host multiple sites by using different certificates on a single IP address, you
need to enable SNI on all sites for that IP address. Otherwise, the site needs its own IP address.

Supported browsers

Most browsers support SNI, but older browsers, such as Internet Explorer® 6 and any Windows XP® browser,
do not support SNI.

Desktop browsers

The following desktop browsers support SNI:

  • Internet Explorer 7 and later

  • Firefox® 2 and later

  • Opera 8 with TLS 1.1 enabled

  • Google Chrome®:

    • Supported on Windows XP on Chrome 6 and later
    • Supported on Vista and later by default
    • Supported on OS X 10.5.7 in Chrome Version 5.0.342.0 and later
  • Chromium® 11.0.696.28 and later

  • Safari 2.1 and later (requires OS X 10.5.6 and later or Windows Vista and later).

Note: No versions of Internet Explorer on Windows XP support SNI.

Mobile browsers

The following desktop browsers support SNI:

  • Mobile Safari for iOS 4.0 and later
  • Android® 3.0 (Honeycomb) and later
  • Windows Phone® 7 and later