Describe Four Techniques Used by Firewalls to Control Access and Enforce a Security Policy

Describe four techniques used by firewalls to control access and enforce a security policy.

Firewall is a part of network system that prevents the internal network communication from unauthorized access while connected to the internet. It is a security measure where all the incoming and outgoing network traffic are measured to find any suspicious activities. The four techniques used by firewalls to control access and enforce security policy are:

1. Service Control: This control determines the type of service that are allowed to access from the network. Traffic are controlled by filtering traffic based on their IP address, port number or protocol used.
2. Direction Control: It determines the direction in which the particular service requests are allowed to flow through the firewall.
3. User Control: Here, access to different services are provided according to the user level. Services are provided according to the user type and their level. Generally, this feature is applied inside the local network. Using, IPsec and other such protocols, this feature can be applied to incoming traffic from external users.
4. Behavior Control: It controls how particular services are used in network. They keep track of particular services in order to find any malicious activity in that service. An example would be blocking spam mails by filtering the address.
5. Describe four generic architectural components of a public communications network.
6. There are four generic architectural components for a public communications network. These components are required in order to make a proper communication network.
7. Subscribers: Subscribers are the devices that are connected to the network. Devices can be telephones and modems.
8. Subscribers Line: It connects the subscribers to the network. They are also known as subscribers loop or local loop. These lines has a range from few kilometers to ten kilometers.
9. Exchanges: These are the switching centers in the network. They act as support for providing service to the subscribers. Switching center that provides service directly to the subscribers are called end office.
10. Trunks: Trunks are branches between exchanges. Trunks carry multiple voice circuits using frequency division multiplexing (FDM) or synchronous time division multiplexing (TDM).

References

Stallings, W., & Case, T. (2013). Business data communications: Infrastructure, networking, and security (7th ed.). Boston: Pearson.