Firewalls chap 3

Perimeter network

Screened subnet connected to a firewall at the edge of a protected network

dual-homed host

A ______-_____ ______ is a fancy term for a computer that has two network interfaces.

indispensable

A critical resource is defined as a software- or hardware-related item that is ______ to the operation of the device or program.

routers

Many operating systems perform IP forwarding, as do ______.

Screened subnet

Network exposed to an external network but partially protected by a firewall

DMZ

One advantage to setting up a ___ with two firewalls is you can control where traffic goes in the three networks.

Screening router

Filters traffic passing between one network to another

router

A ______ determines where packets should go through an interface and which should be blocked based on a set of rules called an access control list.

DMZ screened subnet

A ___ ______ ______ is a network of publicly accessible servers that is connected to the firewall but is outside the internal network being protected.

NAT router

A ___ ______ converts publicly accessible IP addresses to private ones and vice versa.

DMZ

A ___ is a network that sits outside the internal network but is connected to the firewall and provides publicly available servers.

deny all approach

A ____ ____ _____ will block everything by default and only specifically allow those services you need on a case-by-case basis.

dual homed-host

A ____ _____-_____is a client computer that is connected to the Internet and hosts firewall software.

bastion host

A _____ ____ needs to have sufficient processor speed and memory to handle the network's present traffic and increased traffic as the network grows.

screening router

A _____ _____ filters traffic to individual computers within the internal network.

tunnel server

A ______ _____ is a server that creates a secure tunnel connection.

reverse firewall

A ______ ______ is a device that monitors information going out of a network rather than trying to block what is coming in.

screened host

A ______ ______ is sometimes called a dual-homed gateway or bastion host.

reverse firewall

A ______ ______ monitors outbound rather than inbound traffic.

scalable

A firewall needs to be _____ so that it can grow with the network it protects.

service network

A subnet that is attached to the firewall and contained in the DMZ is called a ______ _______.

Dual-homed host

A workstation with an internal interface and an external Internet interface

Stateful failover

Backup services are provided by maintaining copies of connection states

tri-homed firewall

The arrangement of a DMZ enclosed by two firewalls is sometimes called a ___-_____ _______.

Failover firewall

Designed to maintain connections in case a primary firewall stops working

Tunnel server

Enables VPN clients to connect to it based on their IP addresses

Three-pronged firewall

Has three interfaces connecting it to the external network, DMZ, and protected LAN

NAT

IPSec and Kerberos are incompatible with ___.

port scanning attack

If you are a victim of a ____ _____ _____, you should review your firewall logs and block access from the "bad" IP addresses.

Port 25

If you are a victim of a harmful e-mail attachments attack, you should use software that scans ____ ___ for SMTP traffic.

strict

If you follow a "____" approach to security, set up application proxy gateways that forward requests on behalf of internal users.

cautious

If you follow a "_____" approach to security, you should set up a stateful instead of a stateless packet filter.

failover firewall

If you want a ______ ______, both models must be compatible so that they can be configured for seamless operation.

Reverse firewall

Inspects and monitors traffic leaving a local network

state update packets

The Cisco PIX Failover Firewall uses ______ ______ ______ to pass data about the state of the current connections between the primary and the failover firewall.

DNS server

The ___ ______ in the DMZ needs only list a limited number of public IP addresses.

tri-homed firewall

The firewall in a DMZ screened subnet is sometimes called a ___-_____ ______.

important configuration file

The most _____ _____ ____ on your firewall is the rules file.

Tri-homed firewall

The use of two firewalls to set up three separate networks

screened subnet

You create a ______ ______ by adding servers that permit public services and combining them to the firewall's subnet.