SNI
Technology & Computing abbreviation · Networking
| Stands for | Server Name Indication |
|---|---|
| Categories | Technology & Computing |
SNI stands for Server Name Indication, a networking abbreviation.
A TLS extension in which the browser names the website it wants at the start of an encrypted connection, letting one IP address host many HTTPS sites with different certificates. Nearly all shared hosting and CDNs depend on it.
Example: Very old clients without SNI support receive the wrong certificate from our shared IP.
Usage notes
Defined in RFC 3546 (2003) and later RFC 6066. The name travels unencrypted, so network operators and censors can see which sites users visit even under HTTPS. Encrypted Client Hello (ECH) is being deployed to hide it. Internet Explorer on Windows XP was a well-known client that lacked SNI support.
Related abbreviations
More networking abbreviations
- SAN – Storage area network
- SD-WAN – Software-defined wide area network
- SDN – Software-defined networking
- SFTP – SSH File Transfer Protocol
- SMB – Server Message Block
- SMTP – Simple Mail Transfer Protocol
- SNMP – Simple Network Management Protocol
- SOA – Start of authority (record)
- SPF – Shortest path first
- SRV – Service (record)
- SSH – Secure Shell
- SSID – Service set identifier