ACL Access Control List

• NTFS security method that defines permissions for individual files and folders, network access, and local users and groups
• Decides which traffic is allowed through the firewall and which is blocked
• each record in a ACL is an ACE access control entry
• Port assignment is how ACL rules are configured
• Port forwarding occurs when the ACL passes a packet through the firewall.

• use when using a web service that needs to be available to users outside your network
• an example would be a server behind a NAT router
• Port triggering is an automated and dynamic form of port forwarding that specifies which port will be used while outbound ports are in use
• allows PCs behind a NAT-enabled router to provide services which would usually require a static IP address
• more secure than port forwarding, but more unstable
• only one user in a network can access a particular service using a specific incoming port
• the software manufacturer must have provided specific port triggering settings for programs
• different port numbers must be used for port forwarding and port triggering
• the PC must make an outgoing connection before a server behind a NAT router can receive incoming ones making this configuration unsuitable
• commonly used when playing multiple-player games