- (Topic 6)
As per RFC 1122, which of the following is not a defined layer in the DoD TCP/IP protocol model?

Correct Answer:B
As per RFC, The DoD TCP/IP protocol model defines four layers, with the layers having names, not numbers, as follows:
Application (process-to-process) Layer:
This is the scope within which applications create user data and communicate this data to other processes or applications on another or the same host. The communications partners are often called peers. This is where the "higher level" protocols such as SMTP, FTP, SSH, HTTP, etc. operate.
Transport (host-to-host) Layer:
The Transport Layer constitutes the networking regime between two network hosts, either on the local network or on remote networks separated by routers. The Transport Layer provides a uniform networking interface that hides the actual topology (layout) of the underlying network connections. This is where flow-control, error-correction, and connection protocols exist, such as TCP. This layer deals with opening and maintaining connections between internet hosts.
Internet (internetworking) Layer:
The Internet Layer has the task of exchanging datagrams across network boundaries. It is therefore also referred to as the layer that establishes internetworking; indeed, it defines
and establishes the Internet. This layer defines the addressing and routing structures used for the TCP/IP protocol suite. The primary protocol in this scope is the Internet Protocol, which defines IP addresses. Its function in routing is to transport datagrams to the next IP router that has the connectivity to a network closer to the final data destination.
Link (network access) Layer:
This layer defines the networking methods with the scope of the local network link on which hosts communicate without intervening routers. This layer describes the protocols used to describe the local network topology and the interfaces needed to affect transmission of Internet Layer datagrams to next-neighbor hosts.
The DoD tcp/ip model DoD model Osi Model

C:\Users\MCS\Desktop\1.jpg
Graphic above from: http://bit.kuas.edu.tw/ REALITY VERSUS THE STANDARD
In real life today, this is getting very confusing. Many books and references will not use exactly the same names as the initial RFC that was published. For example, the Link layer is often times called Network Access. The same applies with Transport which is often times
called Host-to-Host and vice versa.
The following answer is incorrect:
The session layer is defined within the OSI/ISO model but not within the DOD model. Being incorrect it made it the best answer according to the question. It does not belong to the DoD TCP/IP Model.
Reference(s) Used for this question: http://www.freesoft.org/CIE/RFC/1122/
http://bit.kuas.edu.tw/~csshieh/teach/np/tcpip/

- (Topic 4)
Which of the following is NOT a common backup method?

Correct Answer:B
A daily backup is not a backup method, but defines periodicity at which backups are made. There can be daily full, incremental or differential backups.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 69).

- (Topic 6)
Which of the following is NOT true about IPSec Tunnel mode?

Correct Answer:B
IPSec can be run in either tunnel mode or transport mode. Each of these modes has its own particular uses and care should be taken to ensure that the correct one is selected for the solution:
Tunnel mode is most commonly used between gateways, or at an end-station to a gateway, the gateway acting as a proxy for the hosts behind it.
Transport mode is used between end-stations or between an end-station and a gateway, if the gateway is being treated as a host??for example, an encrypted Telnet session from a workstation to a router, in which the router is the actual destination.
As Figure 1 shows, basically transport mode should be used for end-to-end sessions and tunnel mode should be used for everything else. (Refer to the figure for the following discussion.)
Figure 1 Tunnel and transport modes in IPSec.
Figure 1 displays some examples of when to use tunnel versus transport mode:
Tunnel mode is most commonly used to encrypt traffic between secure IPSec gateways, such as between the Cisco router and PIX Firewall (as shown in example A in Figure 1). The IPSec gateways proxy IPSec for the devices behind them, such as Alice's PC and the HR servers in Figure 1. In example A, Alice connects to the HR servers securely through the IPSec tunnel set up between the gateways.
Tunnel mode is also used to connect an end-station running IPSec software, such as the Cisco Secure VPN Client, to an IPSec gateway, as shown in example B.
In example C, tunnel mode is used to set up an IPSec tunnel between the Cisco router and a server running IPSec software. Note that Cisco IOS software and the PIX Firewall sets tunnel mode as the default IPSec mode.
Transport mode is used between end-stations supporting IPSec, or between an end-station and a gateway, if the gateway is being treated as a host. In example D, transport mode is used to set up an encrypted Telnet session from Alice's PC running Cisco Secure VPN Client software to terminate at the PIX Firewall, enabling Alice to remotely configure the PIX Firewall securely.
AH Tunnel Versus Transport Mode
Figure 2 shows the differences that the IPSec mode makes to AH. In transport mode, AH services protect the external IP header along with the data payload. AH services protect all the fields in the header that don't change in transport. The header goes after the IP header and before the ESP header, if present, and other higher-layer protocols.
In tunnel mode, the entire original header is authenticated, a new IP header is built, and the new IP header is protected in the same way as the IP header in transport mode.
Figure 2 AH tunnel versus transport mode.
AH is incompatible with Network Address Translation (NAT) because NAT changes the source IP address, which breaks the AH header and causes the packets to be rejected by the IPSec peer.
ESP Tunnel Versus Transport Mode
Figure 3 shows the differences that the IPSec mode makes to ESP. In transport mode, the IP payload is encrypted and the original headers are left intact. The ESP header is inserted after the IP header and before the upper-layer protocol header. The upper-layer protocols are encrypted and authenticated along with the ESP header. ESP doesn't authenticate the IP header itself.
NOTE
Higher-layer information is not available because it's part of the encrypted payload.
When ESP is used in tunnel mode, the original IP header is well protected because the entire original IP datagram is encrypted. With an ESP authentication mechanism, the original IP datagram and the ESP header are included; however, the new IP header is not included in the authentication.
When both authentication and encryption are selected, encryption is performed first, before authentication. One reason for this order of processing is that it facilitates rapid detection and rejection of replayed or bogus packets by the receiving node. Prior to decrypting the packet, the receiver can detect the problem and potentially reduce the impact of denial-of- service attacks.
Figure 3 ESP tunnel versus transport mode.
ESP can also provide packet authentication with an optional field for authentication. Cisco IOS software and the PIX Firewall refer to this service as ESP hashed message authentication code (HMAC). Authentication is calculated after the encryption is done. The current IPSec standard specifies SHA-1 and MD5 as the mandatory HMAC algorithms.
The main difference between the authentication provided by ESP and AH is the extent of the coverage. Specifically, ESP doesn't protect any IP header fields unless those fields are encapsulated by ESP (tunnel mode). Figure 4 illustrates the fields protected by ESP HMAC.
Figure 4 ESP encryption with a keyed HMAC. IPSec Transforms
An IPSec transform specifies a single IPSec security protocol (either AH or ESP) with its corresponding security algorithms and mode. Example transforms include the following:
The AH protocol with the HMAC with MD5 authentication algorithm in tunnel mode is used for authentication.
The ESP protocol with the triple DES (3DES) encryption algorithm in transport mode is used for confidentiality of data.
The ESP protocol with the 56-bit DES encryption algorithm and the HMAC with SHA-1 authentication algorithm in tunnel mode is used for authentication and confidentiality. Transform Sets
A transform set is a combination of individual IPSec transforms designed to enact a specific security policy for traffic. During the ISAKMP IPSec security association negotiation that occurs in IKE phase 2 quick mode, the peers agree to use a particular transform set for protecting a particular data flow. Transform sets combine the following IPSec factors:
Mechanism for payload authentication??AH transform
Mechanism for payload encryption??ESP transform IPSec mode (transport versus tunnel)
Transform sets equal a combination of an AH transform, plus an ESP transform, plus the IPSec mode (either tunnel or transport mode).
This brings us to the end of the second part of this five-part series of articles covering IPSec. Be sure to catch the next installment.
Cisco Press at: http://www.ciscopress.com/articles/printerfriendly.asp?p=25477 and
Source: TIPTON, Harold F. & KRAUSE, MICKI, Information Security Management Handbook, 4th Edition, Volume 2, 2001, CRC Press, NY, Pages 166-167.

- (Topic 4)
Contracts and agreements are often times unenforceable or hard to enforce in which of the following alternate facility recovery agreement?

Correct Answer:D
A reciprocal agreement is where two or more organizations mutually agree to provide facilities to the other if a disaster occurs. The organizations must have similiar hardware and software configurations. Reciprocal agreements are often not legally binding.
Reciprocal agreements are not contracts and cannot be enforced. You cannot force someone you have such an agreement with to provide processing to you.
Government regulators do not accept reciprocal agreements as valid disaster recovery sites.
Cold sites are empty computer rooms consisting only of environmental systems, such as air conditioning and raised floors, etc. They do not meet the requirements of most regulators and boards of directors that the disaster plan be tested at least annually.
Time Brokers promise to deliver processing time on other systems. They charge a fee, but cannot guaranty that processing will always be available, especially in areas that experienced multiple disasters.
With the exception of providing your own hot site, commercial hot sites provide the greatest protection. Most will allow you up to six weeks to restore your sites if you declare a disaster. They also permit an annual amount of time to test the Disaster Plan.
References:
OIG CBK Business Continuity and Disaster Recovery Planning (pages 368 - 369) The following answers are incorrect:
hot site. Is incorrect because you have a contract in place stating what services are to be provided.
warm site. Is incorrect because you have a contract in place stating what services are to be provided.
cold site. Is incorrect because you have a contract in place stating what services are to be
provided.

- (Topic 3)
Which of the following would be LESS likely to prevent an employee from reporting an incident?

Correct Answer:B
The reporting process should be centralized else employees won't bother. The other answers are incorrect because :
They are afraid of being pulled into something they don't want to be involved with is incorrect as most of the employees fear of this and this would prevent them to report an incident.
They are afraid of being accused of something they didn't do is also incorrect as this also prevents them to report an incident.
They are unaware of the company's security policies and procedures is also incorrect as mentioned above.
Reference : Shon Harris AIO v3 , Ch-10 : Laws , Investigatio & Ethics , Page : 675.

- (Topic 1)
Which of the following is most appropriate to notify an internal user that session monitoring is being conducted?

Correct Answer:D
This is a tricky question, the keyword in the question is Internal users.
There are two possible answers based on how the question is presented, this question could either apply to internal users or ANY anonymous/external users.
Internal users should always have a written agreement first, then logon banners serve as a constant reminder.
Banners at the log-on time should be used to notify external users of any monitoring that is being conducted. A good banner will give you a better legal stand and also makes it obvious the user was warned about who should access the system, who is authorized and unauthorized, and if it is an unauthorized user then he is fully aware of trespassing. Anonymous/External users, such as those logging into a web site, ftp server or even a mail server; their only notification system is the use of a logon banner.
References used for this question:
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 50.
and
Shon Harris, CISSP All-in-one, 5th edition, pg 873