What are the four network access control lists (NAC) types? There are four different NAC types: Permit List, Deny List, Permit Any, and Deny Any. What is a modem pool? A modem pool is a group of modems that are assigned to a single user. What is the purpose of using a modem pool? The purpose of using a modem pool is to simplify the administration process. What are the benefits of using a modem pool? The benefits of using a modem pool include the following: –Simplifies the administration process.