Which of the following LAN topologies offers the highest availability?
Correct Answer: C
In a full mesh topology, all network nodes are individually connected with each other, providing the highest availability. A partial mesh topology can sometimes be used to offer some redundancy. 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 106).
Question 762
Which of the following choices describe a condition when RAM and Secondary storage are used together?
Correct Answer: C
Explanation/Reference: Virtual storage a service provided by the operating system where it uses a combination of RAM and disk storage to simulate a much larger address space than is actually present. Infrequently used portions of memory are paged out by being written to secondary storage and paged back in when required by a running program. Most OS's have the ability to simulate having more main memory than is physically available in the system. This is done by storing part of the data on secondary storage, such as a disk. This can be considered a virtual page. If the data requested by the system is not currently in main memory, a page fault is taken. This condition triggers the OS handler. If the virtual address is a valid one, the OS will locate the physical page, put the right information in that page, update the translation table, and then try the request again. Some other page might be swapped out to make room. Each process may have its own separate virtual address space along with its own mappings and protections. The following are incorrect answers: Primary storage is incorrect. Primary storage refers to the combination of RAM, cache and the processor registers. Primary Storage The data waits for processing by the processors, it sits in a staging area called primary storage. Whether implemented as memory, cache, or registers (part of the CPU), and regardless of its location, primary storage stores data that has a high probability of being requested by the CPU, so it is usually faster than long-term, secondary storage. The location where data is stored is denoted by its physical memory address. This memory register identifier remains constant and is independent of the value stored there. Some examples of primary storage devices include random-access memory (RAM), synchronous dynamic random-access memory (SDRAM), and read-only memory (ROM). RAM is volatile, that is, when the system shuts down, it flushes the data in RAM although recent research has shown that data may still be retrievable. Contrast this Secondary storage is incorrect. Secondary storage holds data not currently being used by the CPU and is used when data must be stored for an extended period of time using high-capacity, nonvolatile storage. Secondary storage includes disk, floppies, CD's, tape, etc. While secondary storage includes basically anything different from primary storage, virtual memory's use of secondary storage is usually confined to high-speed disk storage. Real storage is incorrect. Real storage is another word for primary storage and distinguishes physical memory from virtual memory. Reference(s) used for this question: Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 17164-17171). Auerbach Publications. Kindle Edition. Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 17196-17201). Auerbach Publications. Kindle Edition. Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 17186-17187). Auerbach Publications. Kindle Edition.
Question 763
Which of the following is NOT a true statement regarding the implementaton of the 3DES modes?
Correct Answer: A
Section: Cryptography Explanation/Reference: There is no DES mode call DES-EEE1. It does not exist. The following are the correct modes for triple-DES (3DES): DES-EEE3 uses three keys for encryption and the data is encrypted, encrypted, encrypted; DES-EDE3 uses three keys and encrypts, decrypts and encrypts data. DES-EEE2 and DES-EDE2 are the same as the previous modes, but the first and third operations use the same key. Reference(s) used for this question: Shon Harris, CISSP All In One (AIO) book, 6th edition , page 808 and Official ISC2 Guide to the CISSP CBK, 2nd Edition (2010) , page 344-345
Question 764
PGP & PEM are programs that allow users to send encrypted messages to each other. What form of encryption do these programs use?
Correct Answer: D
Question 765
Which of the following is an Internet IPsec protocol to negotiate, establish, modify, and delete security associations, and to exchange key generation and authentication data, independent of the details of any specific key generation technique, key establishment protocol, encryption algorithm, or authentication mechanism?
Correct Answer: B
Section: Cryptography Explanation/Reference: RFC 2828 (Internet Security Glossary) defines the Internet Security Association and Key Management Protocol (ISAKMP) as an Internet IPsec protocol to negotiate, establish, modify, and delete security associations, and to exchange key generation and authentication data, independent of the details of any specific key generation technique, key establishment protocol, encryption algorithm, or authentication mechanism. Let's clear up some confusion here first. Internet Key Exchange (IKE) is a hybrid protocol, it consists of 3 "protocols" ISAKMP: It's not a key exchange protocol per se, it's a framework on which key exchange protocols operate. ISAKMP is part of IKE. IKE establishs the shared security policy and authenticated keys. ISAKMP is the protocol that specifies the mechanics of the key exchange. Oakley: Describes the "modes" of key exchange (e.g. perfect forward secrecy for keys, identity protection, and authentication). Oakley describes a series of key exchanges and services. SKEME: Provides support for public-key-based key exchange, key distribution centres, and manual installation, it also outlines methods of secure and fast key refreshment. So yes, IPSec does use IKE, but ISAKMP is part of IKE. The questions did not ask for the actual key negotiation being done but only for the "exchange of key generation and authentication data" being done. Under Oakly it would be Diffie Hellman (DH) that would be used for the actual key nogotiation. The following are incorrect answers: Simple Key-management for Internet Protocols (SKIP) is a key distribution protocol that uses hybrid encryption to convey session keys that are used to encrypt data in IP packets. OAKLEY is a key establishment protocol (proposed for IPsec but superseded by IKE) based on the Diffie- Hellman algorithm and designed to be a compatible component of ISAKMP. IPsec Key Exchange (IKE) is an Internet, IPsec, key-establishment protocol [R2409] (partly based on OAKLEY) that is intended for putting in place authenticated keying material for use with ISAKMP and for other security associations, such as in AH and ESP. Reference used for this question: SHIREY, Robert W., RFC2828: Internet Security Glossary, may 2000.
