Which of the following server contingency solutions offers the highest availability?
Correct Answer: D
Explanation/Reference: Of the offered technologies, load balancing/disk replication offers the highest availability, measured in terms of minutes of lost data or server downtime. A Network-Attached Storage (NAS) or a Storage Area Network (SAN) solution combined with virtualization would offer an even higher availability. Source: SWANSON, Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems, December 2001 (page 49).
Question 368
Which common backup method is the fastest on a daily basis?
Correct Answer: B
Section: Risk, Response and Recovery Explanation/Reference: The incremental backup method only copies files that have been recently changed or added. Only files with their archive bit set are backed up. This method is fast and uses less tape space but has some inherent vulnerabilities, one being that all incremental backups need to be available and restored from the date of the last full backup to the desired date should a restore be needed. 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).
Question 369
Packet Filtering Firewalls examines both the source and destination address of the:
Correct Answer: A
Packeting filtering firewalls are devices that enforce administrative security policies by filtering incoming traffic as well as outgoing traffic based on rules that can include the source and/or destination addresses. "Outgoing data packets" is incorrect. Firewalls filter incoming as well as outgoing traffic. This is sometimes called Egress and Ingress filtering. "Incoming data packets only" is incorrect. (see previous explantion) "User data packet" is incorrect. A packet filtering firewall does not typicallly look into the data portion of the packet. References CBK, p. 464 AIO3, pp. 482 - 484
Question 370
Which of the following technologies has been developed to support TCP/IP networking over low-speed serial interfaces?
Correct Answer: B
Section: Network and Telecommunications Explanation/Reference: Serial Line IP (SLIP) was developed in 1984 to support TCP/IP networking over low-speed serial interfaces. 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 114).
Question 371
Which backup method is additive because the time and tape space required for each night's backup grows during the week as it copies the day's changed files and the previous days' changed files up to the last full backup?
Correct Answer: A
The Differential Backup Method is additive because the time and tape space required for each night's backup grows during the week as it copies the day's changed files and the previous days' changed files up to the last full backup. Archive Bits Unless you've done a lot of backups in your time you've probably never heard of an Archive Bit. An archive bit is, essentially, a tag that is attached to every file. In actuality, it is a binary digit that is set on or off in the file, but that's crummy technical jargon that doesn't really tell us anything. For the sake of our discussion, just think of it as the flag on a mail box. If the flag is up, it means the file has been changed. If it's down, then the file is unchanged. Archive bits let the backup software know what needs to be backed up. The differential and incremental backup types rely on the archive bit to direct them. Backup Types Full or Normal The "Full" or "normal" backup type is the most standard. This is the backup type that you would use if you wanted to backup every file in a given folder or drive. It backs up everything you direct it to regardless of what the archive bit says. It also resets all archive bits (puts the flags down). Most backup software, including the built-in Windows backup software, lets you select down to the individual file that you want backed up. You can also choose to backup things like the "system state". Incremental When you schedule an incremental backup, you are in essence instructing the software to only backup files that have been changed, or files that have their flag up. After the incremental backup of that file has occured, that flag will go back down. If you perform a normal backup on Monday, then an incremental backup on Wednesday, the only files that will be backed up are those that have changed since Monday. If on Thursday someone deletes a file by accident, in order to get it back you will have to restore the full backup from Monday, followed by the Incremental backup from Wednesday. Differential Differential backups are similar to incremental backups in that they only backup files with their archive bit, or flag, up. However, when a differential backup occurs it does not reset those archive bits which means, if the following day, another differential backup occurs, it will back up that file again regardless of whether that file has been changed or not. Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 69. And: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 9: Disaster Recovery and Business continuity (pages 617-619). And: http://www.brighthub.com/computing/windows-platform/articles/24531.aspx
