Apache HSTS

When a user visits your website, the above header will load first and the expiration time is 2 years (63072000 in seconds).

 1# Optionally load the headers module:
 2LoadModule headers_module modules/mod_headers.so
 3<VirtualHost 67.89.123.45:443>
 4Header always set Strict-Transport-Security “max-age=63072000; includeSubdomains;”
 5</VirtualHost>
 6...
 7...
 8...
 9<VirtualHost *:80>
10[…]
11ServerName example.com
12Redirect permanent / https://example.com/
13</VirtualHost>
...

More details in https://medium.com/@sslsecurity/how-to-enable-hsts-on-apache-nginx-and-lighttpd-8b0c64155911