1. Allow Established Connections: This rule allows any traffic that is part of an established connection. For example, if a web server has sent a response to a client, all subsequent traffic from the client to the web server will be allowed.
2. Deny Unsolicited Inbound Traffic: This rule blocks any inbound traffic that is not part of an existing connection. This is used to prevent malicious traffic from entering the network.
3. Allow Outbound Traffic: This rule allows all outbound traffic from the network. This is used to ensure that users can access the internet.
4. Block Unauthorized Services: This rule blocks any services that are deemed to be unauthorized. For example, a company may block access to certain websites or services that are not related to business operations.
5. Set Access Control Lists: Access control lists (ACLs) are used to set specific rules for network traffic. For example, an ACL can be used to allow only certain types of traffic from specific IP addresses.