Procedure: Using a Responder to block access to a URL from a specific subnet
Create the responder action
In the Expression below, I am creating a HTML response that will respond with the blocked URL, the CLIENT IP and the CLIENT subnet, which is based on a 24-bit mask.
Create a Responder policy
In the expression below, I am checking if the red URL is being accessed and if the subnet (again 24-bit mask) is in the subnet that is not permitted.
Bind the Policy to the vServer
This is a simple process, click the + symbol on Policies, select Responder and bind the responder policy that you’ve created.
From a blocked client
Check the reverse to ensure permitted clients are not blocked. The naming conventions for the NetScaler entities used in this blog post are not recommended in a production environment.