Chapter 17: Physical Security 435
- A. Signature files are used by IDS systems to match traffic against known attacks to deter-
mine if an attack has been found or if normal traffic is present. - A. An anomaly-based NIDS is designed to look for deviations from known traffic patterns
and behaviors on the network. Such NIDSs need to be tuned to the network they are con-
nected to. - B. Multihomed firewalls are defined typically as having three or more network connections.
- B. A multihomed firewall can be used to create a DMZ as can two separate firewalls. In
either case, a buffer zone between public and private networks is created. - A. Networks are separated into different zones of trust through the use of firewalls, with
the most typical setup being public and private networks on either side. - C. SMTP is primarily intended to transfer e-mail messages from e-mail servers and clients.
These ports may be open on the typical firewall to allow the flow of e-mail traffic. - D. Ports 161 and 162 are used by the SNMP protocol and can be verified via a banner grab
if the service is running and present. - C. Port 80 is associated with HTTP and will usually be allowed to pass through firewalls
unimpeded. - C. A bastion host is a hardened dedicated system that traffic is filtered through prior to
entering or exiting the network. - C. A packet filtering firewall works at layer 3 of the OSI model.
- C. Stateful inspecting firewalls analyze the status of traffic.
- A. An IP address will in some cases allow a website to be accessed through a firewall
whereas a URL would not.
Chapter 17: Physical Security
- C. Tailgating is an attack where an intruder follows an approved individual into a facility.
Devices such as mantraps can thwart this attack. - B. Alarms are a detective control in that they can detect and react to an action but not pre-
vent an intrusion. - C. A fence should be at least 6-feet tall to deter a determined intruder from entering a facility.
- C. A bollard is a barrier that prevents cars and trucks from passing it to enter a facility.
- A. Liability is a huge issue for dogs and security considering the fact that they may attack
and cannot discern attackers without human intervention.
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