Detecting IPv6 Clients
You can configure Apache HTTPD to set an environment variable if the client is using IPv6:
- httpd.conf
- Set an environment variable if access is IPv6
SetEnvIfNoCase REMOTE_ADDR "^0-9a-f+$" IPV6_USER=1
If Server Side Includes are enabled, you can modify page content based on whether the client is using IPv4 or IPv6:
Hello client from <!--#echo var="REMOTE_ADDR" --> <br> <!--#if expr="$IPV6_USER" --> <b>You are using IPv6. Good!</b> <!--#else --> <b>You are not using IPv6.</b> <!--#endif -->