What’s SNI? Server Name Indication is a important part of SSL that oftentimes goes beneath the radar. SNI is what permits several sites to exist on the exact same IP address. With no SNI, every hostname would need its own IP address in order to get an SSL certificate to be set up. But, SNI solves this issue.

Back in the olden times, which in online years implies 2007, you’d fix the dilemma of multiple sites being hosted on same IP address together with name-based hosts. Fundamentally, when a customer requests a specific site, it employs a exceptional HTTP header that contains the planned hostname. In response, the host matches this pointer to the planned site and transfers the user there.

Where this breaks down is if HTTPS enters the image. The HTTP header which included the planned hostname would not be downloaded until after the handshake has been finished, meaning that the host would not know which site to create the link to.

Server Name Indication is an extension into the SSL/TLS protocol which enables multiple SSL certificates to be hosted on one IP address. The manner SNI does this is by simply integrating the HTTP header to the SSL handshake.

Ahead of Server Name Indication was made, every site that you wished to encrypt had to have a unique IP address. This was unbelievably pricey.