Hi Malith,What you're referring to is what we call "CNAME Reuse" and it's supported by us with some limitations, i.e. SSL/TLS support may not be available depending on the use case. You can read more about it in this article.As for redirecting the domains, this can be done quite easily using our Application Delivery Rules.The rule action can be based on many different matching filters and criteria, host header is one of them.Keep in mind this will work only for clients/browsers that make use of SNI extension, otherwise, the host header may not be present and results won't be as expected.
Hope this helps,
All you'll have to do is to point slac.lk on your domain settings to the given Imperva CNAME for www.srilankan.com. Due to the fact you'll be reaching the same origin that is configured for www.srilankan.com, you shouldn't need to do anything else as all traffic will start reaching your server via the WAF profile configured for www.srilankan.com. You won't need any redirections as you're already hitting the right target. You only need to make sure your server will be capable of serving requests that are being sent to host slac.lk.If you'd like to turn all requests to be made to the new host instead, then a rewrite host rule will be needed.Here's an example: