1. A system for controlling multicast geographic distribution, the system comprising: a memory that stores instructions; a processor that executes the instructions to perform operations, the operations comprising: selecting a multicast channel for distributing content in a content distribution network; identifying an access zone in the content distribution network, wherein the access zone applies a geographic restriction to content; distributing an exclusion policy for the content to a multicast enabled router; denying, based on the exclusion policy, a request for the content from a client system located within an area subject to the geographic restriction that is applied by the access zone; and ignoring, at the multicast enabled router, a multicast join message from the client system based on the exclusion policy, wherein the multicast join message is ignored from the client system if an address of the client system matches a prefix contained within the exclusion policy.