Cyber Security: Firewalls Quiz

Proxy Servers

A server that acts as a sort of "middle man" between clients and resources. Resources are contacted by the Proxy Server and data is relayed back to the client. Often used to bypass Web filters and provide anonymity.

Virtual Private Network (VPN)

A server that acts as a sort of "middle man" between clients and resources. Resources are contacted by the Proxy Server and data is relayed back to the client. Often used to bypass Web filters and provide anonymity.

Software Firewall

Allows incoming traffic based on program name, port number, or system service name.

Port Forwarding

An application of NAT by which one IP Address and port number combination are redirected to another. Port Forwarding can be useful if you have a limited number of external IP Address, but external users require access to multiple LAN servers.

Firewall Appliances

Firewall appliances are preloaded devices installed between a private network and a public network. Stand alone machines Firewall appliances route traffic between networks. Usually between a private network and the Internet, but can be used to separate internal networks as well. Firewall appliances modify the outgoing traffic's private IP Address in the IP header of the packets to the appliance's public IP Address.

Firewall

Firewalls are systems designed to prevent unauthorized access to individual computers or private networks and allow authorized traffic to pass.

Multiple Interfaces

Multiple interfaces on Firewall appliances allow multiple networks to connect to each other. These interfaces allow the appliance to manage traffic between multiple networks.

Network Address Translation (NAT)

NAT allows an entire LAN to access the Internet with only one public IP Address. Firewall appliances modify the outgoing traffic's private IP Address in the IP header of the packets to the appliance's public IP Address. The appliance maintains a NAT table to determine the route of returning packets. NAT also translates a public IP Address into a private IP Address to allow Internet users to access a private network or DMZ.

Enterprise level appliances

Often have modular interfaces to allow a variety of types of connections.

Packet Filtering

Packet filtering occurs at the Network Layer. It is the process of allowing or denying packets on individual network interfaces. Packet filtering is based on source and destination addresses, ports, or protocols.

When can port forwarding be useful?

Port Forwarding can be useful if you have a limited number of external IP Address, but external users require access to multiple LAN servers.

Stateful Inspection

Stateful Inspection occurs up to the Application Layer. It is a technology that monitors the state of active connections to distinguish legitimate packets. Packets are allowed through the firewall based on source and destination addresses, ports, protocols, and applications

Demilitarized Zones (DMZ)

Utilizes multiple interfaces. A DMZ is a subnetwork that provides access to an organization's external facing services from the Internet. A DMZ employs a separate private IP scheme than the LAN.

What does Software based firewalls allow incoming traffic based on?

program name, port number, or system service name