SNI

Server Name Indication

An extension to the TLS (Transport Layer Security) protocol that allows multiple SSL/TLS certificates to be served on the same IP address.

Traditionally, SSL/TLS certificates have been associated with IP addresses rather than domain names. This means that in order to serve a website securely over HTTPS, the website owner needed to have a unique IP address for each domain they wanted to secure. This was not always practical or cost-effective, particularly for smaller websites or web hosting providers.

SNI allows multiple SSL/TLS certificates to be associated with a single IP address by including the domain name in the initial TLS handshake. This means that when a user requests a secure connection to a server, the server can present the appropriate SSL/TLS certificate based on the requested domain name.

SNI is now widely supported by modern web browsers and servers and has become the standard method for serving multiple SSL/TLS certificates on a single IP address. It has helped to reduce the cost and complexity of providing secure web hosting services and has made it easier for website owners to secure their websites with SSL/TLS encryption.

• Abbreviation: SNI