SNI in Tomcat

Server Name Indication (SNI) in Tomcat 8.5 and 9 allows the server to use multiple SSL certificates on a single HTTPS port by mapping them to the hostname of incoming requests. This blog post guides users through configuring SNI in Tomcat 9 by creating self-signed certificates for different companies and configuring the Tomcat server to respond with the appropriate certificate based on the hostname. The configuration process involves modifying the server.xml file to include a <Connector> element that references the certificates, setting a default SSL host, and using the Apache Portable Runtime for improved performance. By testing the setup through a hosts file modification, users can verify that Tomcat correctly assigns certificates based on the requested hostname, demonstrating SNI's capability to manage multiple certificates and provide secure connections for various domains.