วันพุธที่ 31 ธันวาคม พ.ศ. 2551

Trouble-shooting Hard Drive Problems - Part 1

It is extremely important not to make or write any changes to data on the hard drive without first verifying the hard drive configuration. Therefore, the first priority when unable to access information on a hard drive is to verify all of the configuration information dealing with the suspect hard drive.

Partition Parameter
Value or Equation

Partition Status
Bootable

Starting Head
1

Starting Sector
1

Starting Cylinder
0

Partition Type
Bigdos (drives greater than 30 MB), otherwise DOS 12

Ending Head
Total Number of Heads -1

Ending Sector
Sectors per Track displayed in Volume Boot Sector

Ending Cylinder
Number of Cylinders set in CMOS - 2

Total # of Sectors
Number of Sectors displayed in Volume Boot Sector

Start Absolute Sector
Number of Sectors per Track in Volume Boot Sector

Boot Signature
55AA

Step One: Make sure that Micro-Scope detects the hard drive

In Micro-Scope, System Configuration, Compare Settings - check to make sure that there is not an asterisk beside the number of hard drives detected value. If there is an asterisk, either the CMOS is set incorrectly, or there is an electronic problem (controller, cable, drive).

Step Two: Compare the BIOS parameters against the drive partition information.

In Micro-Scope, System Configuration, System Information - note the information displayed for the hard drive, specifically the parameters for the drive in question. Compare these parameters to the parameters in the MBR display under Micro-Scope, System Configuration, Partition Display using the following formula:

System Information
Master Boot Record

Cylinders
Ending Cylinder + 2

Heads
Ending Head + 1

Sectors
Sectors Per Track

If the information does not match, either the partition information is corrupt, or the CMOS setup or controller BIOS setup (if one exists) is incorrect, or there is a problem communicating with the drive.

Step Three: Check the drive functionality

In Micro-Scope, Diagnostics, Fixed Disk Tests - check the information in the Fixed Disk Selected window. Make sure that the proper drive type, model, and native parameters are showing in this window. If any of the information is incorrect, there is an electronic problem. Check the cable, controller and drive, re-seating all connections, and repeat the above procedure. After correcting the electronic problem, perform a read test on the first 10 cylinders of the drive. If any errors occur, then this is the most likely cause of the drive failure. Perform a read of the entire drive to determine if the errors are electronic in nature, or physical in nature. Electronic problems will result in the errors displayed not always being the same type or in the same location on the drive. If the problem is electronic, replace the cable, controller, and finally drive electronics and repeat the read test until no errors occur. If the error is physical, use an INT 13 type editor (such as Norton Advanced Editor), to block the entire drive and write the information to a daisy chained drive set to the same parameters as the faulty drive.

The next step, after the drive passes the read test on the first 10 cylinders, is to check the original partition setup of the drive.

Step Four: Check for the physical location of the master boot sector and the volume boot sector.

In Micro-Scope, Utilities, Fixed Disk Editor - use the FIND feature to search the last two bytes of each cylinder for a boot signature (55 AA). The first location where a boot signature should be found would be at cylinder 0, head 0, sector 1 (the master boot sector). The second location where a boot signature should be found is at cylinder 0, head 1, sector 1 (the volume boot sector). It is also possible to use the FIND feature to locate the volume boot sector by searching for MSDOS (in DOS based systems) or MSWIN (in Windows95 systems).

If there is a duplicate copy of the master boot sector found before the location of the volume boot sector, then it is possible that a boot virus has infected the hard drive in the system. The Rebuild Master Boot feature of Micro-Scope will eliminate any boot sector virus. Be sure to boot the system to the Micro-Scope diskette and immediately do a cold reboot of the system after using the Rebuild Master Boot feature.

If the volume boot sector is found in a location other than cylinder 0, head 1, sector 1, count the actual number of sectors before the volume boot sector, and compare that value to the value for the sectors per track displayed in the partition table described in step 2. If the values match, the most likely cause of the system failure is an incorrect CMOS setup. In this case the CMOS needs to be reset to the values indicated by the partition table described in step 2, remembering to use the formula described in step 2 when doing so. If the values do not match, set the CMOS Sectors Per track to the number of sectors counted before the volume boot sector and continue to the next step.

Step Five: Check the partition tables to make sure they are correct

Reboot the system to Micro-Scope and go to System Configuration, Partition Tables. Check the information displayed in the master boot record to see if there is any obvious corruption (that is, excessively large numbers, all partitions non-bootable, etc.) If there is no obvious corruption in the master boot record, then perform step 2 again. If the information matches at this point, go to step 6. If the information does not match, then set the sectors per track in the Master Boot Record to the number of sectors per track currently set in CMOS, set the starting head to 1, starting sector to 1, and starting cylinder to 0, and write the information to the drive.

Step Six: Verify the Master Boot Sector information

Display the Volume Boot Sector and use the values for heads and sectors per track (on the right half of the screen) to perform step 2 again.

If the values match, then the volume boot sector is probably okay. If any values in the Master Boot Record do not match the table to the right, reset the values to match the values in the table, and write to the drive.

If the values still do not match, both the Master Boot Record and the Volume Boot Record are probably corrupt. At this point, e-mail Technical Support for help in this situation. Future articles will provide more insight into the repair procedure.

Step Seven: Check the FATs

Check to see if the first FAT starts on the sector just beyond the volume boot sector. Use the find feature in the Fixed Disk Editor to search for F8 FF FF in the first three bytes of each sector. The first occurrence should be on sector two of head one. Continue to search until the second FAT is found, indicated by the second occurrence of F8 FF FF. Note the location of the cylinder, head and sector of the second FAT.

Based on the start of the second FAT, and the start of the first FAT, calculate how many sectors are in the first FAT. If necessary, read each sector starting at the first sector of the first FAT, keeping a count of the sectors that have been read until F8 FF FF is seen in the upper left of the HEX display, which would indicate the start of the second FAT. After calculating the sectors per FAT, compare this value to the value in the volume boot sector. If the values match, the drive should be accessible through DOS at this point.

Step Eight: Attempt to access the drive

Boot to a DOS-bootable floppy diskette and attempt to access the drive. If the root directory and sub-directories on the hard drive are readable at this point, then attempt to boot to the drive. If the drive boots at this point, the problem has been corrected. If the drive is still not bootable, e-mail the Micro 2000 Technical Support department for help.

Disclaimer - The Micro 2000 Tech Tip is a free service providing information only. While we use reasonable care to see that this information is correct, we do not guarantee it for accuracy, completeness or fitness for a particular purpose. Micro 2000, Inc. shall not be liable for damages of any kind in connection with the use or misuse of this information.

Micro 2000 Inc has been helping to solve the day-to-day challenges that IT departments face in order to keep their businesses operational as well as profitable for over 14 years. The company's primary goal is to put the customer first - through feature-rich, simple-to-use IT tools that can help IT administrators manage their jobs more effectively.

For more advice and free articles be sure to visit: <a target="_new" href="http://www.micro2000.co.uk">http://www.micro2000.co.uk</a>

The Top 10 Must-Have Laptop Accessories

You've laid out good money for your laptop computer, but you're not done spending just yet.

There are a few more laptop accessories you may want to consider to make the package complete.

1: Laptop Case / Bag

As the newest member of the mobile computing force, you're required to take an oath of safe computing.

And that starts with investing in the most important of laptop accessories - a laptop bag. You can't very well go traipsing around the world with your laptop exposed to the elements.

When it comes to laptop bags, you can spend $25 for a small case made from less expensive materials on up to several hundred dollars for one made of top-grain cowhide.

However, in the end, the most important consideration is whether your case can hold your laptop, plus all the other goodies that go with it (like the ones described here).

2: Software

Did your laptop come with software? If so, did it come with the right software - the software you actually need to perform whatever tasks you need to perform?

Don't just assume you have everything you need. You'll probably need to add some software, as well as go online to update the software that was included.

3: A Real USB Mouse

Trackpads and eraser nubs that fill an obvious need. However, given the option, most people would rather user a real mouse.

If you stop and think for a moment, you're likely to realize that many places where you'll be computing actually are suitable for a real mouse.

So one of the most useful laptop accessories you can buy is a USB mouse, keep it in your bag, and use it whenever you're able.

4: A Cat5 Ethernet Cable

Your built-in Ethernet port won't do you much good if you get to your hotel room, discover an Ethernet connection, and don't have a cable. Some hotels provide them; others don't. Always come prepared with the right cable.

5: A Standard Telephone Cable

The same holds true for your modem connection. If you don't have a cable to get you from your computer to the phone jack, you're not going anywhere in cyberspace.

6: Disposable Cleansing Cloths

Over time, the display on your laptop is going to get dusty, or even smudgy. You're playing Russian roulette with your laptop if you attempt to clean your display with paper towels and spray cleaners.

Instead, use disposable cleansing cloths. These essential laptop accessories are designed specifically to clean laptop displays. Always have a stash on hand.

7: USB Drive

A USB drive is a storage device about the size of your thumb that plugs directly into a USB port.

Capacity-wise, they're relatively small - usually well under 100 MB. However, they're very useful for moving files quickly and easily from one computer to another, e.g., moving a PowerPoint presentation from your laptop to your business associate's laptop.

A USB drive also makes a great temporary backup medium for the really important files you create on the road.

8: Blank CD-R Discs

You've just finished your big sales presentation. Someone from the audience approaches you afterward and asks for a copy of the presentation.

You'll make a better impression if you:

a) ask the person for their email address and tell them you'll email the presentation later

b) ask for their physical address and tell them you'll mail a CD later

c) burn them a CD of the presentation on the spot.

In case you didn't figure it out, the answer is c. Always be prepared with these inexpensive laptop accessories.

9: Stereo Headset

It's great to be able to watch DVD movies no matter where you are. Imagine watching your favorite flick at 30,000 feet.

There's just one problem.

The family in the row behind you has absolutely no interest in hearing the dialog from Pulp Fiction.

Do yourself and everyone around you a favor. When you're watching movies or listening to music in public, use your headphones.

10: Security Device

Laptop security devices come in many shapes and sizes.

For example, most laptops include a security dock that allows you to attach your laptop to some immovable object via cable, much like you'd lock up your bicycle outside the grocery store.

About The Author

Thinking of buying a laptop computer? 'How To Buy A Laptop' is the definitive online guide that will teach you everything you need to know. Don't buy the wrong machine! Check out ==> <a href="http://HowToBuyALaptop.com" target="_new">http://HowToBuyALaptop.com</a>

How to Read CRT Tube Part Numbers

All picture tubes, whether monochrome or color type are identified by a specific code consisting of numbers and letters. The codes are different from each other because different tubes have different characteristics.

For example, a certain monitor colour picture tube may have the designation, M34AFA63X03 that can breakdown into 6 parts: M/34/AFA/63/X/03

Part 1: Application

Computer monitor tubes start with the letter "M&quot; while for a TV picture tube, it start with &quot;A&quot;.

Part 2: Screen diagonal measure in centimeters (cm)

The &quot;34&quot; means the diagonal viewing measure is a minimum of 34cm which refers to 14&quot; tube, 36cm is 15&quot;, 41cm is 17&quot; and so on.

Part 3: Family code

The three letters &quot;AFA&quot; designate a family of tubes that have similar physical and electrical characteristic. These letters are assigned alphabetically beginning with &quot;AAA&quot;, followed by &quot;AAB&quot;, &quot;AAC&quot; etc.

Part 4: Family number

The number 63 shows a specific tube within the family code. A different number is assigned to tubes within the same family that have different neck diameters, for example a single digit would be a monochrome tube, but this two-digit number shows it is colour.

Part 5: Phosphor Type

The fifth symbol gives the phosphor designation. The letter X here corresponds to P22 for colour picture tubes. Colour monitor tubes can have any other single letter (excluding I, O, or W) to designate other phosphor type for various applications. For monochrome pictures, the phosphor symbol is WW, corresponding to P4. Monochrome monitor tubes also can use WW or some other two-letter combination (excluding I and O).

Part 6: Integral neck components

The sixth symbol is assigned only for tubes having integral neck components, such as the deflection yoke. The specs are only apply to a particular tube manufacturer. The primary consideration here is winding inductance. The yoke coils have different sensitivity i.e. deflection per Amp in both horizontal and vertical.

Jestine Yong is a electronic repairer and writer. For more information about electronic repair please visit his website at <a target="_new" href="http://www.noahtec.com">http://www.noahtec.com</a>

War of the Disks: A Close-in Analysis of the Hard Disk Drive vs. the Solid State Disk

Much has been written about solid state disks (SSDs) becoming the next big thing1 in the IT industry(1). But as to whether or not we have enough knowledge of how it will revolutionize the industry is a different question. How much do we really know about SSDs? If we are to ask people on the streets, it wouldn't come as a surprise that they dont know much of what an SSD is. Even if they do know, most probably it would be limited to a USB pen drive, a CompactFlash or a Secure Digital card, which are more on the consumer side of the storage industry.

Technically speaking, they are not wrong. Most web definitions describe an SSD as a high-performance plug-and-play storage device that contains no moving parts. Therefore, given that most of the aforementioned mobile disk storage devices contain no movable parts, they can certainly be categorized as SSDs.

But then again, there's more to SSDs than being a non-volatile device. The purpose of this article is to give readers a clearer picture of what an SSD is, its usage as well as its difference when pitted against the predominant data storage device at present - the hard disk drive (HDD). More than its non-volatility, this article will reveal how much potential SSDs have in optimizing the performance of the computing system.

SSD Defined

Here are several ways the SSD is defined:

"A solid state disk (SSD) is electrically, mechanically and software compatible with a conventional (magnetic) hard disk or winchester. The difference is that the storage medium is not magnetic (like a hard disk) or optical (like a CD) but solid state semiconductor such as battery backed RAM, EPROM or other electrically erasable RAM-like chip. This provides faster access time than a disk, because the data can be randomly accessed and does not rely on a read/write interface head synchronising with a rotating disk. The SSD also provides greater physical resilience to physical vibration, shock and extreme temperature fluctuations. The only downside is a higher cost per megabyte of storage."(2)

"Abbreviated SSD, a solid state disk is a high-performance plug-and-play storage device that contains no moving parts. SSD components include either DRAM or flash memory boards, a memory bus board, a CPU, and a battery card. Because they contain their own CPUs to manage data storage, they are a lot faster (18MBps for SCSI-II and 44 MBps for UltraWide SCSI interfaces) than conventional rotating hard disks ; therefore, they produce highest possible I/O rates. SSDs are most effective for server applications and server systems, where I/O response time is crucial. Data stored on SSDs should include anything that creates bottlenecks, such as databases, swap files, library and index files, and authorization and login information."(3)

For the rest of the article, we will compare the HDDs and Flash-based SSDs. The latter are the most popular type of SSDs employed by the military, aerospace, industrial and embedded systems industries.

Mortality Rate

Hard disk failure is a common occurrence in this age of desktops and notebooks. A lot of horror stories have been told, passed around and even published about how valuable data was lost and the agony of trying to retrieve or at least save a portion of the crashed hard drive. It is during this time that people wonder, why do hard disks fail?

The reason is simple - wear and tear. Just like any good old machine with mechanical components, HDDs tend to deteriorate over time. HDDs consist of rotating, magnetically coated disks, known as platters, that are used to store data. This rotating motion of the mechanical arms results in much wear and tear after long periods of use. The operational lifespan of a computer HDD is over three years.(4)

A Flash-based SSD is different. Although the most common Flash chips have around 300,000 write cycles, the best Flash chips are rated at 1,000,000 write cycles per block. On top of that, Flash SSD manufacturers employ different ways to increase the longevity of the drives. In some cases, they use a "balancing" algorithm to monitor the number of times each disk block has been written, which greatly extends the operational lifespan of the drive. Furthermore, these manufacturers also designed special "wear-leveling" algorithms where once a certain percentage threshold for a given block is reached, the SSD will swap the data in that block with the data in another block that has exhibited a "read-only-like" characteristic in the background. This reduces performance lag and avoids further wearing off of the blocks and thrashing of the disk. Even with usage patterns of writing/reading gigabytes per day, a Flash-based SSD should last several years, depending on its capacity. Add to that the inclusion of a DRAM cache in the disk architecture that further enhances its operational capabilities as well as lifespan.

Speeding Up

With the very fast paced lifestyle these days, most businesses are time-bound and cannot afford a slowing down in their transactions. This makes speed of HDDs a crucial point in technological purchases. The typical access time for a Flash based SSD is about 35 - 100 s, whereas that of a rotating disk is around 5,000 - 10,000 s. That makes a Flash-based SSD approximately 100 times faster than a rotating disk.

This however raises another point - what's the benefit of a high-speed SSD when the entire system cannot support it? The evolution of CPUs in terms of performance has far surpassed the development of the data storage system. The HDD is actually limiting the potential of a computer system when they are not able to keep up with the performance of the other components, particularly the CPU. If an HDD is replaced by a high-speed SSD, the performance would significantly improve. The resulting system would be a high-powered set-up that can go beyond the demands of high-speed business or military environments.

Size Matters

To be a true plug-in replacement for HDDs, Flash-based SSDs are manufactured in standard 2.5" and 3.5" form factors. 2.5" SSDs are normally used in laptops or notebooks while the 3.5" form factors are used in desktops, or in JBOD or other SAN/NAS/DAS configurations. They can often be used to replace traditional disks in storage arrays or in a server's internal disk bays. Flash-based SSDs certainly fit the storage needs of most embedded systems that require much smaller form factors.

Reliability

In terms of reliability, conventional HDDs pale when compared to SSDs. The absence of mechanical arms and spinning platters is the reason behind its reliability. In demanding environments, SSDs provide the type of ruggedness required for mobile applications. Unlike the HDD, SSD's can withstand extreme shock and vibration with data integrity and without any danger of data loss. This feature is very important in industrial applications where exposure to highly combustible materials and electromagnetic radiation are typical. Their ability to deliver unnerving performance in extreme conditions also makes SSD play a vital role in military operations, be it in defense, aerospace or aviation applications. Military applications require, in most cases, an operating temperature range of -60?C to +95?C. Shock, vibration, and temperature ratings of HDDs cannot comply with military standards, only SSDs can.

Power Play

In addition to speed, reliability and mortality rate being positively affected by the SSD's non-volatility, they also consume much less power than traditional HDDs. No additional power is required to activate the platters or the mechanical arms present in most HDDs. Its power consumption is practically only a fraction of a hard disk drive.

Heat Dissipation

Along with the lower power consumption, there is also much lesser heat dissipation for systems using Flash-based SSDs as their data storage solution. This is due to the absence of heat generated from the rotating/movable media. This certainly proves to be the one of the main advantages of Flash-based SSDs relative to that of a traditional HDD. With less heat dissipation, it serves as the ideal data storage solution for mobile systems such as PDAs, notebooks, etc. Users can do away with large cooling fans, internal power supply and batteries for large storage arrays in storage area networks.

Cost Considerations

Of course, everything comes with a price. Based on a cost-benefit logic, it is but expected that something with very impressive features be priced higher than something that offers fewer benefits. SSDs as being a bit more pricey than the traditional hard disk drive may be one of the compelling reasons why up to now it hasn't gained as much popularity as it should be getting with all its brilliant functions.

While the use of SSDs today have mostly been limited to industrial and military implications, enterprise are now looking closely at SSDs for implementing tiered storage and optimizing their storage architectures.

To quote from the Solid State Disks Buyers Guide published by storagesearch.com, "In fact the SSD is replacing servers and software licenses. SSDs can be used either to speed up the response time of existing applications as an alternative to buying more servers, or to reduce the number of servers and software licenses deployed. The economics can be compellingly in favor of an SSD deployment". The industry is also expecting more breakthroughs as higher memory capacities and faster performance are now being produced for a wider array of choices fit for any mission-critical application.

Analysts foresee a rapidly closing gap between HDD and flash SSD pricing (see related article "Are Flash Solid-State Disks Ready for the Enterprise"(5) ). This vision is also bolstered by a recent announcement(6) of electronic giant Samsung that they will invest heavily in improving their flash and DRAM production lines and flash SSD equipped laptops. Only time will tell if we will witness widespread commercial adoption of SSDs.(end)

This article has been reprinted from <a href="http://www.e-disk.com/articles/war_of_the_disks_1.html" target="_blank">www.e-disk.com</a>

________

(1)Read article at http://www.storagesearch.com/view40.html
(2)Source: http://www.sparcproductdirectory.com/curtisart.html
(3)Source: http://www.webopedia.com/TERM/S/solid_state_disk.html
(4)Source: http://www.cmu.edu/corporate/news/2004/0604_critter.html
(5)Source: http://www.bitmicro.com/press_resources_flash_ssd_enterprise.php
(6)Source: http://www.techworld.com/storage/news/index.cfm?NewsID=3967&email

Joanne De Peralta is Marketing Communications Specialist for <a href="http://www.bitmicro.com" target="blank">BiTMICRO Networks</a>. You may contact her at <a href="mailto:jdeperalta@bitmicro.com">jdeperalta@bitmicro.com</a>

Introduction to Dedicated Servers

A dedicated server is a single computer on a web-hosting network that is leased or rented, and dedicated to just one customer. A service provider monitors the computer's hardware, network connectivity, and routing equipment, while the customer generally controls and maintains the server software. Dedicated servers are most often used by those who've outgrown typical hosting accounts and now require massive amounts of data space and bandwidth, those with mission critical web sites, web hosting companies, or those who have special needs. Dedicated servers are housed in data centers, where service providers can monitor them close-up and have hands-on access to them.

The primary advantage of using a dedicated server over a typical shared hosting account is the sheer amount of resources and control available to you, the customer. In many cases, the client is at liberty to install whatever software they desire, giving them greater flexibility and administrative options. Dedicated server clients do not share resources, as those with shared hosting plans do; but rather, are at liberty to use all the resources available to them.

Managed Servers vs. Unmanaged Servers

There are two types of dedicated servers available today: Managed Dedicated Servers and Unmanaged Dedicated Servers.

An Unmanaged Dedicated Server leaves nearly all the management duties of running a server in the purchaser's control. The customer in this case, updates software on their own, applies necessary patches, performs kernel compiles and operating system restores, installs software, and monitors security. With this type of dedicated server, the consumer is solely responsible for day-to-day operations and maintenance. The service provider, in turn, monitors the network, repairs hardware problems, and troubleshoots connectivity issues. Additionally, some service providers offer partial management of services, such as network monitoring, software upgrades and other services, but leave the general upkeep of the server in the hands of the client. An unmanaged dedicated server is best for someone with server management experience.

A Managed Dedicated Server is generally more proactively monitored and maintained on the part of the service provider. When renting or leasing a managed server, the service provider or host carries out the responsibility of software updates and patches, putting security measures in place, performing hardware replacements, and also monitoring the network and its connection for trouble. In other words, when utilizing a managed dedicated server, the host provider will perform both hardware and software operations. A managed dedication server solution works well for the customer with limited server management experience or limited time in being able to perform the duties necessary to keep a server running and online.

Technical Aspects In Choosing A Server

When choosing a dedicated server, there are several things to consider: Operating System, Hardware options, Space and bandwidth.

The Operating System of a server is similar to that on your own personal computer; once installed, the operating system enables one to perform tasks more simply. There are a bevy of server operating systems available today including Linux-based and Windows-based software. The operating system you choose should be directly relational to what operations your server will be performing, which types of software you'll need to install and also, what you're more comfortable with.

Hardware Options are also something to consider when choosing a dedicated server. You'll need to pick a processor that's up to the task, the amount of memory you wish installed, firewall options, and the size of the hard drive.

A certain amount of bandwidth is generally included when renting or leasing a dedicated server. Once you ascertained how much bandwidth you will require, you can adjust that limit with your service provider. The space you'll be given is generally directly relational to the size of your hard drive. Some hosts also give clients the choice of uplink port speed (usually 10Mbps/100Mbps).

About The Author

Emmanuel Eichler

<a href="http://HostLead.com" target="_new">HostLead.com</a> - Webmaster

Business Web Hosting Directory

วันอังคารที่ 30 ธันวาคม พ.ศ. 2551

Hard Drive Selection

Perhaps the biggest mistake people make when building their computer(s) is to underestimate the importance of the hard disk drive (HDD). In our modern society, bigger is synonymous with better, so when you go to buy a hard drive you look at how "big" it is, its data capacity. But is that all you should be considering when buying your hard drive?

Like every other component of your computer, the HDD is far too complex a system to describe in any sort of detail here, but hopefully by the end of this article you will know what to look for when you go to buy your new hard drive.

There are 4 primary aspects to look at in a hard drive (in order of importance):

<li>Rotational frequency and average seek time

<li>Buffer size

<li>Internal/external transfer rates

<li>Capacity

Rotational frequency has become a large selling point (5400/7200/10000/15000RPM) recently, so you shouldn't have too much difficulty finding out what the rotational frequency of your HDD is when you go to buy it. Now of course the faster it spins, the faster it can read from the disk (there are other advantages also), but be aware that the faster it spins, the more wear is put on the drive, and the more likely it is to encounter errors and malfunctions later in life. Hard drives are pretty much the only systems within your computer that have moving parts (CD-ROM, floppy disk drives, and fans also have moving parts, but they're all cheap and if they break you won't lose all the data you've accumulated over the course of owning your computer, be sure to back up your data regularly!).

If you know anything about physics or engineering, then you know that moving parts produce friction and wear, and a faster spinning platter (the part that holds the data and spins) means more friction, and therefore more wear on your drive. Of course the faster it spins the faster it can read data from the platter. So what can you do? well again you backup your data as much as possible and you get the fastest spinning drive money can buy (which is 7200RPM for ATA devices (the sort you are buying) and 15000RPM for SCSI and some Serial ATA devices (you might get Serial ATA, that depends on your motherboard)). So look for a "7200RPM" label on the drive you're thinking of getting, it's important!

The "buffer" I'm referring to is the transfer buffer that temporarily stores data to read from or write to the hard drive. The reason for this is that the bus (data channel between the hard drive and the motherboard) can only handle so much information at a time, and it takes a long time for the data to be found and retrieved from a platter (random seek time), so it takes a big chunk of the requested data and stores it in a very fast data buffer to be sent at the bus's convenience. So with a larger buffer you can queue more data for transfer over the bus without having to keep sending requests to slowly find more data from the platters. Some newer drives come with as much as 8MB of buffer capacity, but it is more common to see 2 or 4MB. Usually a drive with a large amount will use that as a selling point and print it on the box/website, otherwise you can assume it has a 2/4MB buffer. My advice is to find one with as much as you can afford.

Now for the transfer rates you're going to need to do some searching, the best way to find these numbers is to go to the manufacturer's website and look at specification sheet for the model you're looking to buy (actually this is the best way to get all the information I've talked about so far). One thing to look out for is that you may read something that says 133MB/s or ATA/133 or SATA150 or 150MB/s, and these are not the numbers you are looking for, those numbers describe the bus connecting the hard drive to the motherboard, and are theoretical peak numbers, which tell us virtually nothing. Also, if you are buying a Maxtor, don't bother looking up actual transfer rates, as Maxtor is apparently afraid to release such information. Not to say Maxtor's are bad drives, actually Maxtor has risen to the top in terms of technical support and they are much more willing to replace broken drives than some other companies, which is important since some ridiculously large amount (something like 10 or 15%) of hard drives are either dead on arrival or die within the first few weeks of use. As with the last two points, when looking at transfer speeds (if you can find them) always try to pick the one with the highest numbers you can afford.

Notice that the first three of the 4 major aspects were all speed related? That was done intentionally to give you a sense of the importance of speed in the hard drive, because they are very very slow creatures, and for your gaming experience you don't need an enormous hard drive so much as a fast one. To increase speed substantially more you can set up a RAID, which is a network of hard drives which (in RAID0 mode) share portions of the same data, such that accessing data takes 1/n time (n = number of hard drives attached) compared to 1 hard drive. To do this you really need a hardware RAID chipset, which are commonly included on higher-end mainboards.

Finally, capacity is an unnecessary nicety. The smallest hard drives you can buy today that are still within those higher speed classes are all about 30GB, which is more than enough for your games. But since games are not everything, and if you happen to be an iTunes member or like to download anime then you will really want some extra space. So I would recommend getting something between 60 and 120GB, any more and you're going to be paying through your teeth, any less and you might be looking to buy a supplementary hard drive in a couple years. And, oh yeah, 300GB hard drives from Maxtor are out, but they are comparatively slow, so I wouldn't recommend getting one for gaming, I like to stick to single platter drives (40-100GB usually), as they produce less heat and are less likely to break down on me.

That is really all you need to know in order to make a good choice when upgrading your hard drive or buying one for a new computer. Of course there are many other resources on the web if you would like more detail on the inner working of hard drives.

About The Author

J A Carpunky <a href="http://www.computer-gaming-system.com" target="_new">http://www.computer-gaming-system.com</a> - visit our website for further information.

Cisco CCNA Certification: Why You NEED Hands-On Practice !

CCNA and CCNP candidates hear it all the time: &quot;you have to get some hands-on experience to pass the exams&quot;.

Candidates tend to think that's just so they can solve the simulator problems, but that's only the more obvious reason.

First, I want to make it clear that I'm not bashing learning from books you have to learn theory before you can really know what's going on in the first place. The key is that to truly understand routing and switching processes, you've got to have that hands-on experience.

So if the simulator questions are the more obvious reason to get hands-on experience, what are the less obvious reasons?

Glad you asked!

You see what happens when things don't go according to the script. One of the biggest problems with learning your skills on software programs such as &quot;router simulators&quot; is that with simulators, things go pretty much as planned.

I have news for you: that doesn't always happen in the real world. While Cisco routers and switches are highly reliable devices, every once in a while you're going to get an unexpected result from a command. Maybe it didn't work after you typed it in maybe it has an effect on your prior configuration that you didn't expect. Maybe you don't know what happened ? you just typed in that command and the router went nuts!

Sooner or later, that's going to happen to you in the real world. And as I tell my students, it's actually a good thing to have happen to you in a lab.

You don't learn to troubleshoot or fine-tune a configuration when everything works perfectly. You don't learn much at all when things go perfectly. And you're practicing to learn!

I often say that great chefs don't learn to cook on cooking simulators they learn in the kitchen, and they burn a lot of meals on the way to greatness. You need to screw up some configs on the way to greatness, and you can't do that on a computer program. You have to be on the real thing.

You build confidence by working with real Cisco routers and switches. Would you want the Super Bowl to be the first football game you ever really played in? Of course not. Then why would you take router configuration exams and be nervous about having to create a VLAN, or troubleshoot an OSPF configuration?

You cannot walk into the testing room a nervous wreck. You must have the attitude that you are already a CCNA or CCNP, and you're just there to make it official. I can tell you from firsthand experience with many students that the way you develop than confidence is to work with the real deal.

You can't buy that confidence, and you can't simulate your way to it. You've got to work with real Cisco routers and switches. By working with the real equipment, you develop the real skills and real confidence you need to pass the CCNA and CCNP exams.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage. The Bryant Advantage sells the world's best CCNA Study Guide in PDF format for only $15 and is the ONLY company specializing in CCNA and CCNP rack rentals, allowing candidates for these certifications to gain vital hands-on experience with full racks of Cisco routers and switches with labs and prices designed just for them. There are also plenty of FREE CCNA and CCNP tutorials! Visit his site at <a target="_new" href="http://www.thebryantadvantage.com">http://www.thebryantadvantage.com</a> today!

Flyback Transformer-How to Locate the ABL Line

Whenever there is a complaint about monitor contrast problem I will check on the flyback transformer ABL (automatic blanking limiter) circuit. Sometimes a weak picture tube might caused contrast problem. If the picture tube is good, I will go straight to the contrast circuit. The question is how do we find where the contrast circuit located? Simple, if you have a datasheet for the video pre- amplifier ic, definitely you can find the contrast pin. For LM1203N video pre-amp ic the contrast pin is located at pin 12. Replace this ic or trace from this circuit to find the cause of the contrast problem.

From experienced, usually capacitors shorted and resistor turned into high ohms were the caused of the problem. A video pre-amplifier can also be defective. To confirm whether is circuit or ic problem, just solder out the contrast pin and switch on the monitor. If the monitor display normal picture (contrast ok) then suspect the abl line circuit. If it remain the same (dim contrast) replace the video pre-amp will usually solve the problem.

The contrast signal came from one of the pin (leg) of a flyback transformer which we called it as abl pin. Many technicians have the difficulty to trace the abl pin because usually a flyback transformer consist of around 10 pins. Some pins are B+, GROUND, AFC, ABL, X-RAY PROTECT, VCC, to HOT, HEATER, horizontal centering and etc. But there is one and simple way that i'm gone to show you how to locate the abl pin. Use two analog multimeters set to x10kohm range. Connect it in series (+ probe to - probe) and measure the flyback transformer from anode (the red cap) to all of the pins under the flyback. You have to desolder all the pin or just remove the flyback from the mainboard in order to get an accurate reading.

If either one of the pin shows a diode reading that is the abl pin. The reason we use two multimeters is because the flyback circuit internally have couple of high voltage diodes connected in series. If you have a schematic diagram or any monitor or television troubleshooting book, you will see that the internal flyback diode are connected in series. By connecting two meters the ouput from the probe is around 24 VOLTS which is enough power to check the flyback internal diodes. After you have determined the abl pin, you can proceed to follow the line and find the bad components that cause the contrast problem.

Television or tv flyback transformer generally have the same design compare to monitor flyback. Whether it is a montblanc flyback transformer, rca, mitsubishi or sony flyback the checking usually is the same.

Jestine Yong is a electronic repairer and a writer. For more electronic repair information please visit his website at <a target="_new" href="http://www.noahtec.com/electronic-repair-articles.htm">http://www.noahtec.com/electronic-repair-articles.htm</a>

วันจันทร์ที่ 29 ธันวาคม พ.ศ. 2551

ABCs Of DVD Drive Abbreviations

The number of different formats available in DVD drives can be confusing to anyone in the market for one. The list is much longer, but to address a few of the common formats, we have DVD-ROM, DVD-R, DVD-RW, DVD+R, DVD+RW, DVD-RAM ,DVD+R DL and DVD?RW. Wow! This list of common formats is long enough, no wonder it's confusing!

What's with all the Formats?!

The reason for various recordable DVD formats is that no one group owns the technology and different groups have chosen to support one technology over another. There is no industrial standard for manufacturers to reference, so for the time being consumers will have a few choices.

The first thing to address is DVD itself, which stands for Digital Versatile Disc. Some may argue that the V stands for Video, but with the capability to store video, audio, and data files, Versatile is definitely the keyword.

Start with the Basics

A DVD-ROM drive is the only one we will address that does not record. ROM stands for Read Only Memory, and refers to the typical drive that can merely read DVDs, as well as CDs (all DVD drives can read CDs). The Lite-On LTD-163-DO-R has attributes representative of your typical DVD-ROM drive, and features a maximum DVD read speed of 16x and a maximum CD read speed of 48x.

Before getting into the different recordable formats, let's address the basics of what the R and RW stand for, regardless of whether there is a + or ? in the middle. R stands for Recordable, which indicates that the disk may be recorded to only once. RW stands for ReWritable, which indicates that the disc may be recorded to more than once, and are generally rated for 1000 rewrites under good conditions.

The DVD-R/-RW format was developed by Pioneer, and was the first format compatible with stand alone DVD players. The group that promotes the technology calls itself the DVD Forum, which is &quot;an international association of hardware manufacturers, software firms, content providers, and other users&quot; with notable members such as Hitachi, Samsung, and Toshiba. The DVD-R/-RW format is based on CD-RW technology and uses a similar approach to burning discs.

The DVD+R/+RW format is a newer format, also based on CD-RW technology, and compatible with a large percentage of stand alone DVD players. The +R/+RW technology is not supported by the DVD Forum, and its main backing comes from a group called the DVD+RW Alliance. The Alliance &quot;is a voluntary group of industry-leading personal computing manufacturers, optical storage and electronics manufacturers&quot; with members such as Dell, Hewlett Packard, Sony, and Phillips Electronics.

The DVD-RAM format is based on PD-RW (Phase-Differential) drives, and actually uses a cartridge to hold the media (just like its PD-RW predecessor). Some DVD-RAM cartridges are double sided, making them ideal for companies to use as system backup, hence DVD-RAM is usually found only in commercial applications, and most end-users won't ever need to use or see this type of drive. The DVD-RAM standard is also supported by the DVD Forum just like the DVD-R/RW format. However, because of its use of a cartridge (limiting it's compatibility), and the scarcity and price of the media used, DVD-RAM is a distant third when compared to the DVD+R/+RW and DVD-R/?RW technology.

The +R/+RW and ?R/-RW formats are similar, and the main difference DVD+R technology has is the ability to record to multiple layers (with its new DVD+R DL format), where DVD-R can only record to one layer (not all +R drives are capable of dual layer burning, but no -R drives are). The Plextor PX-504U is an example of an external DVD+R/+RW drive capable of recording single layer discs in the +R/+RW format, but also able to read discs recorded by a DVD-R drive.

What is DVD?RW?

DVD?RW is not actually a separate format, but the designation given to drives capable of both ?R/?RW and +R/+RW operation. This type of drive is typically called a &quot;Dual Drive&quot; (not to be confused with a &quot;Double Layer&quot; drive) since it can write to both the +R/+RW and ?R/?RW formats. The Samsung TS-H552 is a DVD?RW drive capable of reading and writing every format discussed so far, and then some. It takes advantage of DVD+R DL (Double Layer) technology available with the +R format, allowing the appropriate media to store virtually double the 4.37 GB capacity of a typical single layer disc.

The other main thing to consider with DVD burners is selecting the correct media. Media for DVD-R, DVD-RW, DVD+R and DVD+RW media may all look the same, but they are slightly different in order to match the specific recording formats. The price of media for either format is generally the same, with RW media costing a good deal more than R media of either format. Double Layer media is even more expensive, and is the only way for an owner of DVD+R DL drive to take advantage of the tremendous capacity increase. As the amount of Double Layer drives increase in the market, the price of the DVD+R DL media is expected to fall with increased production of the media. DVD Burners (as these drive are often referred to) can be picky about the media supported, so be sure to choose your media wisely.

DVD in a Nutshell

DVD-ROM : Reads DVD discs

DVD+R : Writes to DVD+R media (will also typically write to CD-R and CD-RW media)

DVD+RW : Writes to DVD+RW media (will also typically write to DVD+R, CD-R and CD-RW media)

DVD+R DL : Writes to DVD+R DL (Double Layer) media (will also typically write to DVD+R, DVD+RW, CD-R and CD-RW media; many Double Layer drives are ALSO dual drives ? that is, able to write to BOTH +R/RW and ?R/RW media)

DVD-RAM : Writes to DVD-RAM cartridges (not in wide use on consumer market ? mainly a business format; can also read PD-RW discs. Will not usually be able to write to any other format including CD-R or CD-RW)

DVD-R : Writes to DVD-R media (will also typically write to CD-R and CD-RW media)

DVD-RW : Writes to DVD-RW media (will also typically write to DVD-R, CD-R and CD-RW media)

DVD?RW : Writes to DVD-RW and DVD+RW media (will also typically write to DVD-R, DVD+R, CD-R and CD-RW media; typically called &quot;Dual Drives&quot; since it can burn to two different DVD formats)

Final Words

This article took a look at the more common formats of DVD drives in order to shed some light on all the choices available. The differences between them all may be subtle, but the compatibility issues can be quite frustrating. The simple answer to anyone considering a drive is to forget about + and ? by themselves, and shoot for universal compatibility with a good DVD?RW with DVD+R DL support.

<a target="_new" href="http://www.geeks.com/pix/techtips.htm">http://www.geeks.com/pix/techtips.htm</a>

What to Do Once You Are Infected with Spyware, Ad-ware or Viruses

What to do once your PC is infected with spyware, ad-ware or viruses

So you've been running a virus program. Or you haven't. (Check my previous article on keeping your computer at top speed by using Avast). Either way, your PC is now infected by spyware/ad-ware, or even worse, a virus. What DO you do?

The easiest method, is, of course, to format. Should you turn on your PC and the infestation is so bad (and some of them are) you need to format, simply slide a windows xp cd you've either bought or burned into your rom drive, re-boot, and go through windows installation. Don't forget to enter your BIOS/CMOS and change your boot sequence so your cd-rom drive boots before your hard drive.

If you've just got a small problem; your computer still runs fine, then you can just clean up your hard drive with any number of programs. There are many out there, but the ones I suggest would be Spybot: Search and Destroy, Lavasoft ad-aware, and Avast Anti-Virus.

All of these programs are free and can be downloaded off download.com . Likely the most user-friendly program would be Avast or Ad-aware. Spybot is a little more of an advanced program. It is still one of the best, but if you have trouble understanding PC problems, you might have troubles understanding how Spybot works. (You could always read the readmes or their forums, however). Microsoft has also released a new program too, which can be downloaded from download.com as well, or whatever your favorite download portal is.

Anyways, once you have one of these programs, start a scan and attempt to remove the infestation. Most of these programs can also schedule a boot time scan. This means your computer will reboot and scan before you load windows. This can help remove most infestations because most spyware/ad-ware/viruses can manifest themselves in windows so well that they cannot be deleted unless you delete them before windows loads or from safe mode.

A boot-time scan is recommended as the first course of action to remove your infestation. Should you continue to experience slower PC speeds, you could try using a virus scanner to not only scan your hard drive, but prevent your PC from getting more spyware. Usually with spyware, once you have even a few files infected, they spread like a virus and attempt to propogate themselves. It's important you have a virus scanner to not only delete old spyware, but prevent new spyware from popping up. Avast is great for this.

Anyways, good luck and good hunting. Use a format as your last course of action. Besides, it's good for your PC at least once a year to format. This re-aligns your partition tables and eliminates corruption as well as fragmentation.

I am a young, aspiring computer engineer into Internet Marketing, hardware, software, web design, SEO and just about anything related to computers. Please come check out my growing PC forum at <a target="_new" href="http://www.markspcforum.com">http://www.markspcforum.com</a>

วันอาทิตย์ที่ 28 ธันวาคม พ.ศ. 2551

Where does technology come from?

Ever wonder where all the cool gadgets come from? Ever wonder who gets to try this stuff out first? Usually the war machine scientists get it first, try it out and find an application by using it for destruction; an obvious outlet for the human species and our desire to blow things up. It then moves into the private sector for important projects like, Microwave Ovens, Nuclear Energy, aviation space travel, telecommunications, Internet (which of course Al gore created first?), even Hummers, the ultimate SUV was created to cruise troops around in, Helicopters, hydrofoils, you name it man it came from military first.

But now we are seeing things move so fast that the general population will be getting the new technologies in some way or another within a few years from discovery and proving of concept. Many things are now being created in private sector and the military is finding great applications for them such as the palm computer technology for Navy Seal Teams, cell phone telemetry tracking. What about the private sector protecting their rights to these advances? Patents? Who cares, by the time you get the thing filed everyone has it, four of your former employees brought it to your competitors, your key vendors sold it or partnered with another company to make it. By this time it is already on the shelves for you and I. The company with the marketing channels and fastest rollout gets the cake, but does not have time to eat it. Remember in the new age the fast eat the slow. The game never stops and people and companies enter and exit the field of their choice at will. With the Internet as a distribution channel a new wiget can be to market in months and delivered in 8-12 hours by Fed Ex if the company has their manufacturing at or near a regional hub. The World is changing and we maybe getting many of these new technologies a lot faster than before. Think about it.

"Lance Winslow" - If you have innovative thoughts and unique perspectives, come think with Lance; <a target="_new" href="http://www.WorldThinkTank.net/wttbbs">www.WorldThinkTank.net/wttbbs</a>

Power and Your PC

The power coming into a computer is the most critical component, and it may be one of the most overlooked. It is just taken for granted that it will always be there and working properly. A top of the line processor and ultra powerful video card do nothing if a system does not receive the ample, stable power it demands. Having quality components providing and regulating the power supplied to a computer is critical, and this brief overview looks at a few areas worth consideration.

Power Supplies

Computer power supplies take the high (110V or 220V) DC voltages from an electrical outlet and convert it to the various lower AC voltages required for a system to operate. The typical voltages required inside a computer are 3.3V, 5V, and 12V, where the 3.3V and 5V lines are generally used to power circuitry, and the 12V line provides power to run items such as hard drives, optical drives, and cooling fans.

Power supplies are sold in terms of their total power output, in terms of wattage. Choosing the correct power supply means not only finding one that will provide enough power for all of the components connected to the system, but also one that is the correct size physically, has enough connections for typical drives and fans, and if necessary, that also has special connections for things such as Serial ATA drives and modern video cards.

Choosing a power supply with enough power shouldn't be much of a problem, as having more power than you need is never a bad thing. Just because a power supply is rated for 400W, or perhaps 600W, does not imply that it is drawing that at any given time. It just indicates the total power available to the various lines inside the computer. For those interested in getting a good idea of their minimum power requirements, this Power Wattage Calculator is a convenient reference. In addition to checking out the total wattage of a power supply, looking for strong amperage ratings on the 3.3V, 5V, and 12V lines is also recommended, as power supplies with identical total power ratings may distribute the power to the various lines in different quantities.

Power supplies come in a few different physical sizes, but the most common are designed to fit the standard ATX and micro ATX (mATX) form factor cases. A typical ATX power supply, such as this Echo-Star 680W unit, measures 3.25&quot; x 6&quot; x 5.5&quot; and features two cooling fans to not only cool the power supply, but to also help draw hot air out of the computer. A typical mATX power supply, such as this A-Power 320W unit, measures 2.5&quot; x 5&quot; x 4&quot; and due to the smaller size features just one cooling fan. mATX cases are generally much smaller than ATX cases, and therefore have smaller power supplies, with generally lower power ratings, and fewer connectors.

The connectors on a power supply also deserve consideration. Most power supplies come with what looks to be an electric octopus of wires hanging off the back surface, and you need to make sure that somewhere in that tangled bundle are all of the connectors you need. The power supply should at least have as many connections as the number of drives, cooling fans, and other items found in the case. Up until recently power supplies had a fixed number of connections, and if you needed more, you needed to use splitters to distribute the power to all the components. Modular power supplies, such as the Ultra X-Connect 500W unit, are now available that eliminate that &quot;electric octopus&quot; all together, and allow the end user to connect just the cables they need. The flexibility of a modular power supply design not only lets you customize the connections to your needs, it also makes for a simple and tidy installation, since there are no extra wires dangling inside the case.

The selection of a high quality power supply may cost more money up front, but down the road it could wind up saving money. Many manufacturers now offer power supplies that consume less energy thanks to high quality internal components, advanced designs, and active power factor correction. These units are now able to provide the same power to the components in a computer, but due to increased efficiency, draw less power from the electrical outlet.

Surge Protectors

Surge protectors are intended to protect your electronics from a brief increase in voltage caused by such things as lightning, rolling blackouts, and heavy drawing electrical equipment. A surge protector reacts to divert the extra electricity to ground, and thus protects your expensive computer equipment from damage. A surge is any increase lasting three nanoseconds or longer, so a surge protector needs to react quickly. Most surge protectors also include a fuse (or breaker), and if the surge is too great to be handled without interruption, the fuse will blow. Although the fuse may be destroyed, it's a small loss compared to what it may have saved.

Surge protectors come in all shapes and styles. Some basic models can even be found at your local dollar store, but offer no more than a few outlets connected to a breaker. No serious protection is obtained, but many people just want more outlets, not protection.

More serious surge protectors will probably cost a bit more than a dollar, but will offer some peace of mind that your equipment is actually being protected. In addition to protecting from electrical surges, some devices include extra features such as conditioning to filter out line noise and ports to protect other lines such as cable television, telephone, and networking.

The Fellowes Smart Surge Power Strip protects up to 10 devices from surges, as well as offering line conditioning and ports to protect your phone line. A highly appealing feature of such a surge protector is that 4 of the ports are designed to accept bulky AC adaptors. For those with surge protectors that weren't designed to be this user friendly, there is still hope in the form of Power Strip Saver Cables. Basically just 7 inch long extension cords, these items can come in very handy when trying to connect multiple AC adaptors to a more traditional surge protector.

Uninterruptible Power Supplies

Many people familiar with Uninterruptible power supplies (UPS) know that they can keep a computer up and running during a total power failure, but don't know what else they do. Most UPSes will also provide protection from voltage surges and sags (when the voltage drops below normal), as well as protection from the possibility of a shift in the electricity's frequency.

UPSes come in two varieties, standby and continuous, although standby versions are far more common and less expensive. A standby UPS allows the devices connected to it to run from the normal electrical connection until a loss of power is detected, at which point it quickly (in a matter of milliseconds) switches to the battery backup of the UPS. A continuous UPS always has the devices connected to it running off of battery power, while the batteries are recharged by the normal electrical connection.

UPSes are sold in terms of their capacity, in terms of VA (voltage multiplied by amperage). This implies that devices connected to the UPS can draw a maximum of so much amperage at a specific voltage. A run time after a power failure is also generally specified for a UPS based on a full load being placed on the device.

Selecting a UPS needs to be based on the intended use? A smaller unit, such as the Fenton 600VA, would be adequate for powering a typical desktop computer, monitor, and smaller peripherals such as a printer and lighting for what they rate as 15-23 minutes at full load. If multiple systems need to be powered, or perhaps there are plans for future expansion that will add to the power demands, a larger unit such as the Tripp Lite 1500VA may be more appropriate. The first two units are intended to be set in close proximity to the devices to be powered, perhaps on the floor behind a desk, but if you are seeking to add a UPS to a server, there are also rackmount solutions such as the Opti-UPS 1100VA.

No matter the application, sizing a UPS may seem overwhelming. One manufacturer, APC, has created a handy UPS Selector Application which will take some of the guess work out of choosing the right UPS for any particular application.

Final Words

A computer system is only as strong as its weakest feature, and many times that distinction falls on the power supply and related components. By choosing a quality power supply, surge protector, and perhaps a UPS, one can make sure that they have adequately strong and stable power to keep their system running now, as well as down the road when upgrades may increase the demand on their system.

Jason Kohrs
<a target="_new" href="http://www.geeks.com">Computer Geeks</a> <a target="_new" href="http://www.geeks.com/pix/techtips.htm">tech tips</a> and <a target="_new" href="http://www.geeks.com/pix/techtips.htm">computer advice</a>

วันเสาร์ที่ 27 ธันวาคม พ.ศ. 2551

Laptop Security -Where?d My Laptop Go?

Laptops are lovely. They are convenient, mobile, powerful and prestigious.

They are also thief magnets. Over 400,000 laptops disappear each year, leaving their owners wondering where they went, what is happening with their data and what to do next.

Some of the laptops are just lost ? left in cabs, at hotels, restaurants and at conferences and events. Many of these laptops (but not all) find their way back to their lucky owners.

Some are stolen by people ? many of them co-workers, service staff or people taking advantage of a &quot;moment of opportunity&quot; ? who just want to have a laptop.

Some are stolen by professional &quot;Laptop Lifters&quot; who may work in teams to steal the laptops for resale.

And others are stolen, not for the laptop itself, which may be a bonus, but for the data on the laptop's hard drive ? financial or identity data or business plans or data.

For example:
<UL><LI>QualComm's CEO had his laptop stolen while he was conducting a Press Conference. Reportedly, some of QualComm's most valuable secrets were on that laptop, unencrypted and only protected by an easily bypassed password. <LI>A Department of State laptop containing high level information on nuclear proliferation was stolen right from State's headquarters. Two administrators were fired and other personnel were reprimanded.</ul> Think about it ? What other piece of equipment or personal possession do we routinely carry around that is worth over a thousand dollars, by itself, and may be worth thousands more in data? Why wouldn't that be attractive to thieves?

A large part of the problem is less on the hardware or software end of things, it's in the HUMAN side of things. By raising our awareness many of the vulnerabilities can be greatly lessened.

There are 3 areas of vulnerability: 1) Securing the actual laptop, 2) Securing the Data, 3) Getting the laptop back.


1) Securing the actual laptop

There are many ways to control the physical security of a laptop.


There are cable locks that can be attached to an immovable object to make it more difficult to just pick up the laptop and walk away. Although these cables can be cut with a bolt cutter, some of them are combined with an alarm that will sound if the cable is cut.


Alarms or motion detectors are also available without the cable locks. They can be set to activate whenever the laptop is moved or when the laptop is moved a certain distance away from a pocket receiver that the owner has, which also alerts the owner. www.anchorpad.com, www.kensington.com, www.computersecurity.com, www.pcguardian.com, www.trackitcorp.com, www.minatronics.com


Use a laptop carrying bag that does not look like a laptop case. Having a laptop case that says IBM or Sony is advertising that you are carrying a highly valuable commodity. Consider using a backpack with your laptop in it in a padded sleeve. One of the prime places for laptop theft is the men's bathroom in airports and convention centers. Another prime place that laptops are stolen is at pay phones in a busy area.


Just as there are pickpocket teams, one of whom distracts you by &quot;accidentally&quot; bumping into you while the other steals your wallet, there are &quot;Laptop Lifters&quot; one of whom will accidentally spill something on you while the other walks off with your laptop. A good rule to follow is: any time there is a diversion near you, put your hand on your laptop.


People usually feel comfortable at conferences and conventions. After all, you are usually surrounded by your peers, and there are often convention staff around to provide security. Often the theft will take place on the second or third day, when IDs for entry are not being checked as stringently, and many of the attendees are NOT wearing their badges. Many times people will leave laptops unguarded on or under conference tables during breaks.


Even if it is not your laptop that is stolen, your PCMIA cards ? modem or wireless connectors ? can be stolen in an instant. Not only is this a loss of value, it's also a real inconvenience.


It's a good idea to engrave your company information prominently on the outside of the laptop and on its carrying case. It makes it less attractive to the thief, because it makes it easy to identify and makes it harder to sell. Having a large or conspicuously colored luggage tag securely affixed makes it less attractive because thieves like to be &quot;invisible.&quot;


You also should be sure to send in that little registration card that came with your laptop. Sometimes a stolen laptop will be sent back to the manufacturer for repair by the person who had innocently bought it from the thief. You may get your laptop back this way.


Don't leave your laptop in your car. If it is visible, you may lose your laptop AND have to pay for the damage to your car. Rental cars are often the special target of thieves, especially at popular restaurants or shopping malls. Plus, the extremes of temperature (both hot AND cold), can either fry your laptop or freeze the LCD screen.


2) Data Security


Losing your laptop may mean you'll have to shell out $1,000 - $3,000 for a new one. Losing your data can be MUCH more serious. Many people ONLY have a laptop, so ALL of their data is on it. Plus, most people don't back up their data as often as they should.


Replacing the data can be a pain. But losing your PERSONAL data, including perhaps your Social Security number, PIN numbers, credit card info, etc can be a form of personal hell.


Here are the steps you should take:


Set a BIOS password. BIOS is the first program to load when you turn on your computer. Your laptop will not boot at all until that password is entered. Although there are ways to bypass this, (there's all kinds of info on the 'Net), it's the first in several layers of security you can institute. (See http://www.lockdown.co.uk/?pg=biospsw&s=articles to see how to set a BIOS password).


Use the NTFS file system (assuming you are using XP). NTFS has strong encryption capabilities not available in FAT or FAT32. Here are a couple of articles that might help you decide: http://windows.about.com/od/filesfoldersdisks/l/aa001231b.htm http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/convertfat.mspx


Prevent data loss through your Infrared port. Do you actually use your infrared port? Do you even know if you have one? If you do have one, your computer can be hacked into all the way across the room! A simple way to disable it is to put a piece of black electrical tape across it. (It's a little dark window, generally on the back of your laptop). Alternatively you can disable the infrared port completely. Because each laptop manufacturer has different steps, search on Google or Yahoo for &quot;Disable Infrared Port&quot; and add your laptop manufacturer's name to the search terms.


Back up your data before you leave your office. That way, if your laptop is lost or stolen, you have not lost your files.


Consider keeping sensitive files off your laptop hard drive. A DVD can hold multiple gigabytes of data and can be carried in your pocket. A USB storage device is also quite handy.


If you are running XP Pro, your can encrypt your data using EFS (Encrypting File System), so it will be totally unreadable without the decryption key. If you don't have the Pro version, you can purchase third party encryption software.|


3) Getting your laptop back.


So the worst has happened and your laptop has disappeared. Hopefully, you have your name and phone number on it somewhere, so it can be returned to you if it was just left in a cab.


If you've taken the right steps before it disappeared, there's a fair chance you will get it back.


Here's what you can do to increase the chance of getting it back:


There are software solutions that allow you to trace your laptop if it ever connects to the Internet. For instance, www.computrace.com/ will give you the IP address wherever your laptop logs on. The cost is under $50. Getting the police to go and recover your laptop is another story, however.


According to some reports, when the police cooperate, recovery is up to 90%!
All in all, the most effective preventative is user awareness. Reportedly, Arthur Andersen CPA firm not only has classes and posters on laptop (and other) security, but they also have roving security personnel who take unattended laptops, cell phones, purses and PDAs off of desks and other unsecure locations, leaving a note behind telling the hapless &quot;victim&quot; where to get their property back. Quite an education, and probably pretty effective in raising awareness!

? Steve Freedman, Archer Strategic Alliances 2005 All Rights Reserved

Steve Freedman Archer Strategic Alliances <a target="_new" href="http://helpprotectmycomputer.com">http://helpprotectmycomputer.com</a>

Intel Celeron vs Pentium

The Celeron and Pentium Processors are two of Intel's best selling CPUs. They are found in a majority of home computer systems. When comparing the two processors it should be first understood that there are different types of Pentium processors - the original Pentium all the way to the Pentium 4 (the latest Pentium processor). The Celeron processors are more or less the same, although you will find them in a wide variety of speeds.

The Intel Celeron processor was always designed to be a low-cost alternative to the Pentium processor line. It is much like a car company that offers various priced cars from the luxury sedan to the economy compact. The Celeron is simply a downgraded Pentium, that almost anyone can afford (it is essentially the compact). To begin, Celeron chips have a smaller L2 cache 9128kb compared with 512kb in the Pentium 4 Northwood, which translates into slower processing speeds. In fact, current Celerons have a clock speed limit of about 2.0GHz, where as the Pentium for is capable of speed in excess of 3.0GHz. In addition, the Pentium runs at a lower core voltage because it is more energy effecient (1.75V vs. 1.5V).

In summary, the Pentium 4 is more powerful than the most advanced Celeron processor on the market. However, Intel has planned it to be this way. Many applications will work just great with a Celeron processor, despite a little less power than the Pentium 4. It is a way to save a little cash when buying a new pc - but don't forget the saying "you get what you pay for." Celeron processors are of good Intel quality, but they will never be as good as the Pentium.

This Celeron vs. Pentium review was brought to you by SciNet Science and Technology Search Engine. SciNet is not affiliated with or specifically endorses the Celeron or Pentium processors or the manufacturer, Intel Corp. Please consult the Celeron and Pentium product information and configuration before you purchase either processor. It is also a good idea to seek other up-to-date product reviews and information as necessary.

Bradley James is a senior editor at <a target="_new" href="http://www.scinet.cc">SciNet.cc</a>, a website containing many helpful consumer electronics review articles. For more information on Celeron and Pentium processor technology, please visit our <a target="_new" href="http://www.scinet.cc/articles/celeron-vs-pentium/celeron-pentium.html">Celeron vs Pentium</a> webpage.

Obsolete Is A Dirty Word (Intel Pentium 64 Bit Microchip)

Get ready everyone, home computers are about to set new LAN speed records! The Intel 64-bit microchip will soon be powering the new line of Pentium 4 computers. This long awaited sizzling fast release will be heading to store shelves across America just in time for the new blazing fast Windows 64-bit operating system. You'll get the 64-bit Pentium microchip, the 64-bit operating system, and that's not all, if you spend all your money, you'll also get all the new 64-bit stellar fast software programs that will leave current versions coughing in the rooster tail of their 64-bit micro-dust.

Yet a startling new poll indicated a majority of respondent(s) were actually upset by the good news from the technology sector.

Here are the fascinating results of the poll:

Respondent(s) gave a 1-10 rating regarding their anticipated personal happiness and productivity that the newer and faster computers would yield. 1 being: "I'm in electronic nirvana, I waited to buy, I was patient and did not up-grade pre-maturely, and now the technology gods have rewarded my computer buying diligence, bestowing upon me a new Intel 64-bit processor, operating system and software as soon as they come out!!" And 10 being: "Don't talk to me I hate you!" The margin of error was +/- 0%. Questionnaires were sent to a scientific sample of 1.

OK it was me. I polled myself. And no I'm not happy. But wait, before you judge me harshly, I should give you some facts about myself that might engender some empathy. First of all, I'm cursed. I don't know how this works, but I hold all power over technological advances. That's right, new technology will not be released to the computer buying public until I finally decide to upgrade...to the old technology. Narcissistic? Hardly. There is a cosmic triggering mechanism that knows. If you happened to be tuned in, it would go a little something like this: "Technology universe heed! Rick has purchased Super Gizmo 3.0. Prepare to launch version 4.0. Wait for my command....Steady... There, he's exceeded the store return policy envelope. Launch upgrade. Brace for impact and greatness of sorrow. That is all."

So I hope you're happy. Because the only reason, that you can go out and buy the new Intel 64-bit P4 wonder machine and all of the wonder programs & software to come, is because I just bought a beautiful 32-bit machine with matching laptop. No, that's ok, you don't have to thank me. It's just a burden that I must carry. I do it stoically and with quiet dignity, normally, but this is a revolutionary advance, a tectonic shift in computing acceleration and I'm going to wail out loud, because I just can't go out and buy another computer and stay married! At least that's how she interprets the vows.

Oh...you think I make too much of this do you? Perhaps. But for those of you who may not be as, how should I say...techno hip... let me explain the speed differential between the present 32-bit sludge processors (like the one I just bought...twice) and the new sleek Intel 64-bit miracle maker.

Picture languishing in a huge super Wal-Mart with two hundred bargain happy shoppers squeezing through 32 cash registers at once. And just to make it really painful, some have price checks and questionable coupons. See yourself in line. A long line. And all you can do to pass the time is inch along reading the "13 Things Wives Never Tell Their Husbands". After awhile, you might get close enough to see another magazine cover with a picture of Jennifer, ...the exact moment she found out about Brad. Go ahead judge Brad, you've got the time. You can even manufacture some contempt for that vixen Angelina. You're not going anywhere, no one is going anywhere. They've only got 32 cash registers open!

Suddenly, one of the cashiers feels the heat, fumbles for the microphone, and makes a garbled announcement. It must be in code, because no one can understand it, yet the next thing you know, everyone is tossing magazines and trampling children, nuns, & puppies. Why? I'll tell you why. Because 32 more cashiers are now open for the next person in line! That makes a grand total of 64 cashiers "processing" transactions instead of 32! The line is moving fast..."Come on people, we're all going home!" And that my friend is how the new Intel 64-bit microchip works. Do you see now why I mourn?

"The analogy is brilliant", you might say, "but how does that translate into reality?" Well, the average home computer user will now be able to print a letter at .005 nanoseconds instead of .006! Think of it. You'll be pulling out your letter from the printer, while I'll still be be pulling out my letter from the printer too, but a whole .001 nanoseconds behind, unless I come up with an ingenious "low tech" way to make up the difference and win.

So go ahead, buy the faster computer, see if I care, I don't mind. One day I'll have that 64-bit, right before the 128's come out. And perhaps you'll be standing with me, in 64-bit hell, wanting my Cosmo, but no, I'm not done reading it yet. I still need to find out the "22 Secrets of True Passion and How To Enlighten Your Idiot Man." And then we'll see who mourns, when I look you in the eye and say, "Go find your own magazine!"

Rick David writes a humor column entitled, <a target="_new" href="http://sandiego.merchantamerica.com/index.php?x=articles&type=is_sd"> "Don't Laugh, It Could Happen To You!"</a> for <a target="_new" href="http://sandiego.merchantamerica.com">http://sandiego.merchantamerica.com</a>

Security Risks and Ways to Decrease Vulnerabilities in a 802.11b Wireless Environment

Introduction

This document explains topics relating to wireless networks. The main topics discussed include, what type of vulnerabilities exist today in 802.11 networks and ways that you can help prevent these vulnerabilities from happening. Wireless networks have not been around for many years. Federal Express has been using a type of wireless networks, common to the 802.11 networks used today, but the general public has recently just started to use wireless networking technology. Because of weak security that exists in wireless networks, companies such as Best Buy have decided to postpone the roll-out of wireless technology. The United States Government has done likewise and is suspending the use of wireless until a more universal, secure solution is available.

Background

What is Wireless?

Wireless LANs or Wi-Fi is a technology used to connect computers and devices together. Wireless LANs give persons more mobility and flexibility by allowing workers to stay connected to the Internet and to the network as they roam from one coverage area to another. This increases efficiency by allowing data to be entered and accessed on site.

Besides being very simple to install, WLANs are easy to understand and use. With few exceptions, everything to do with wired LANs applies to wireless LANs. They function like, and are commonly connected to, wired Ethernet networks.

The Wireless Ethernet Compatibility Alliance [WECA] is the industry organization that certifies 802.11 products that are deemed to meet a base standard of interoperability. The first family of products to be certified by WECA is that based on the 802.11b standard. This set of products is what we will be studying. Also more standards exist such as 802.11a and 802.11g.

The original 802.11 standard was published in 1999 and provides for data rates at up to 2 Mbps at 2.4 GHz, using either FHSS or DSSS. Since that time many task groups have been formed to create supplements and enhancements to the original 802.11 standard.

The 802.11b TG created a supplement to the original 802.11 standard, called 802.11b, which has become the industry standard for WLANs. It uses DSSS and provides data rates up to 11 Mbps at 2.4 Ghz. 802.11b will eventually be replaced by standards which have better QoS features, and better security.

Network Topology

There are two main topologies in wireless networks which can be configured:

Peer-to-peer (ad hoc mode) ? This configuration is identical to its wired counterpart, except without the wires. Two or more devices can talk to each other without an AP.

Client/Server (infrastructure networking) ? This configuration is identical to its wired counterpart, except without the wires. This is the most common wireless network used today, and what most of the concepts in this paper apply to.

Benefits of Wireless LANs

<ul>

<li>WLANs can be used to replace wired LANs, or as an extension of a wired infrastructure. It costs far less to deploy a wireless LAN than to deploy a wired one. A major cost of installing and modifying a wired network is the expense to run network and power cables, all in accordance with local building codes. Example of additional applications where the decision to deploy WLANs include:

<li>Additions or moves of computers.

<li>Installation of temporary networks

<li>Installation of hard-to-wire locations

</ul>

Wireless LANs give you more mobility and flexibility by allowing you to stay connected to the Internet and to the network as you roam.

Cons of Wireless LANs

Wireless LANs are a relatively new technology which has only been around since 1999. With any new technology, standards are always improving, but in the beginning are unreliable and insecure. Wired networks send traffic over a dedicated line that is physically private; WLANs send their traffic over shared space, airwaves. This introduces interference from other traffic and the need for additional security. Besides interference from other wireless LAN devices, the 2.4 GHz is also used by cordless phones and microwaves.

Security Issues of WLANs

<ul>

<li>War-driving


War-driving is a process in which an individual uses a wireless device such as a laptop or PDA to drive around looking for wireless networks. Some people do this as a hobby and map out different wireless networks which they find. Other people, who can be considered hackers, will look for wireless networks and then break into the networks. If a wireless is not secure, it can be fairly easy to break into the network and obtain confidential information. Even with security, hackers can break the security and hack. One of the most prevalent tools used on PDAs and Microsoft windows devices is, Network Stumbler, which can be downloaded at <a href="http://www.netstumbler.com." target="_new">http://www.netstumbler.com.</a> Equipped with the software and device, a person can map out wireless access points if a GPS unit is attached. Adding an antenna to the wireless card increases the capabilities of Wi-Fi. More information can be found at: <a href="http://www.wardriving.info" target="_new">http://www.wardriving.info</a> and <a href="http://www.wardriving.com" target="_new">http://www.wardriving.com</a> to name a few.

<li>War-chalking


War-chalking is a method of marking wireless networks by using chalk most commonly. War-driving is usually the method used to search for networks, and then the person will mark the network with chalk that gives information about the network. Some of the information would include, what the network name is, whether the network has security, and possibly the contact information of who owns the network. If your wireless network is War-chalked and you don't realize it, your network can be used and/or broken into faster, because of information shown about your network.

</ul>

Eavesdropping & Espionage

Because wireless communication is broadcast over radio waves, eavesdroppers who just listen over the airwaves can easily pick up unencrypted messages. These intruders put businesses at risk of exposing sensitive information to corporate espionage. Wireless LAN Security ? What Hackers Know That You Don't www.airdefense.net Copyright 2002

Internal Vulnerabilities

Within an organization network security can be compromised by ways such as, Rouge WLANs (or Rouge Aps), Insecure Network Configuration, and Accidental Associations to name a few.

Rouge Access Points ? An employee of an organization might hook up an access point without the permission or even knowledge of IT. This is simple to do, all a person has to do is plug an Access point or wireless router into an existing live LAN jack and they are on the network. One statistic in 2001 by Gartner said that, &quot;at least 20 percent of enterprises already have rouge access points.&quot; Another type of attack would be if, someone from outside the organization, enters into the workplace and adds an Access Point by means of Social Engineering.

Insecure Network Configurations- Many companies think that if they are using a firewall or a technology such as VPN, they are automatically secure. This is not necessarily true because all security holes, big and small, can be exploited. Also if devices and technologies, such as VPNs, firewalls or routers, are mis-configured, the network can be compromised.

Accidental Associations ? This can happen if a wireless network is setup using the same SSID as your network and within range of your wireless device. You may accidentally associate with their network without your knowledge. Connecting to another wireless LAN can divulge passwords or sensitive document to anyone on the neighboring network. Wireless LAN Security ? What Hackers Know That You Don't www.airdefense.net Copyright 2002

Social Engineering ? Social Engineering is one of the most effective and scariest types of attacks that can be done. This type of attack really scares me and can be done for many other purposes besides compromising security in wireless networks. A scenario: Someone dressed up as a support person from Cisco enters the workplace. The secretary sees his fake credentials and lets him get pass the front desk. The impersonator walks from cubicle to cubicle, collecting user names and passwords as he/she goes. After finding a hidden corner, which seems to be lightly traveled, he plugs an insecure Access Point into the network. At the same time he configures the Access Point to not broadcast its SSID and modifies a few other settings to make it hard for the IT department to find this Rouge Access Point. He then leaves without ever being questioned by anyone because it looks like he just fits in. Now, all he has to do is be within 300 feet from the access point, (more if he added an antenna), and now has access to all kinds of secure documents and data. This can be a devastating blow to any corporation and could eventually lead to bankruptcy if the secrets of the company were revealed to competitors.

Bruce Schneier came to my classroom and said the following about Social Engineering, &quot;Someone is just trying to do their job, and be nice. Someone takes advantage of that by targeting this human nature. Social Engineering is unsolvable.&quot;

Securing Wireless Networks

According to Bruce Schneier and others such as Kevin Mitnick, you can never have a totally secure computing environment. What is often suggested is to try and control the damage which can be done if security is breached. One can try many different tools on the market which can help prevent security breaches.

WEP ? WEP supports both 64 and 128-bit keys. Both are vulnerable, however, because the initialization vector is only 24-bits long in each case. Its RC4 algorithm, which is used securely in other implementations, such as SSL, is quite vulnerable in WEP. <a href="Http://www.infosecuritymag.com/2002/jan/cover.shtml" target="_new">Http://www.infosecuritymag.com/2002/jan/cover.shtml</a> Wireless Insecurities By Dale Gardner. Different tools exist to break WEP keys, including AirSnort, which can be found at www.airsnort.net. Although this method is not a secure solution, it can be used to help slowdown an attacker if other means are not possible financially or otherwise.

VPN and IPSec- IPSec VPNs let companies connect remote offices or wireless connections using the public Internet rather than expensive leased lines or a managed data service. Encryption and authentication systems protect the data as it crosses the public network, so companies don't have to sacrifice data privacy and integrity for lower costs. A lot of VPN's exist on the market today. An important note about VPNs is, interoperability does not really exist, and whatever you use for your server has to be the same brand as your clients most of the time. Some VPNs include:

<ul>

<li>Borderware

<li>BroadConnex Networks

<li>CheckPoint

<li>Cisco

<li>Computer Associates

</ul>

DMZ ? Adding this to your network enables you to put your wireless network on an untrusted segment of your network.

Firewalls ? Firewalls are all over the place. Firewalls range from hardware to software versions. By adding a firewall between the wireless network and wired network helps prevent hackers from accessing your wired network. This paper doesn't go into specifics about different firewalls and how to set them up, but there are many. Some of the firewalls include:

<ul>

<li>ZoneAlarm (an inexpensive based software firewall) Zonelabs.com

<li>Symantec has many different firewalls depending what you require.

</ul>

PKI - Public-key infrastructure (PKI) is the combination of software, encryption technologies, and services that enables enterprises to protect the security of their communications and business transactions on the Internet. What is PKI? <a href="http://verisign.netscape.com/security/pki/understanding.html" target="_new">http://verisign.netscape.com/security/pki/understanding.html</a>

Site Surveys ? Site Surveys involve using a software package and a wireless device to probe your network for Access Points and security risks.

Proactive Approaches

Since wireless technology is insecure, companies or anyone can take a proactive approach to try and identify hackers trying to gain access via wireless networks.

Honeypots ? are fake networks setup to try and lure in hackers. This enables administrators to find out more about what type of techniques hackers are using to gain access. One product is Mantrap created by Symantec.

&quot;ManTrap has the unique ability to detect both host- and network-based attacks, providing hybrid detection in a single solution. No matter how an internal or external attacker tries to compromise the system, Symantec ManTrap's decoy sensors will deliver holistic detection and response and provide detailed information through its system of data collection modules.&quot;

<a href="http://enterprisesecurity.symantec.com/products/products.cfm?ProductID=157" target="_new">http://enterprisesecurity.symantec.com/products/products.cfm?ProductID=157</a>

Intrusion Detection ? Intrusion Detection is software that monitors traffic on the network. It sounds out a warning if a hacker it trying to access the network. One such free product is Snort.

&quot;Before we proceed, there are a few basic concepts you should understand about Snort. There are three main modes in which Snort can be configured: sniffer, packet logger, and network intrusion detection system. Sniffer mode simply reads the packets off of the network and displays them for you in a continuous stream on the console. Packet logger mode logs the packets to the disk. Network intrusion detection mode is the most complex and configurable configuration, allowing Snort to analyze network traffic for matches against a user defined rule set and perform several actions based upon what it sees.&quot; <a href="http://www.snort.org/docs/writing_rules/chap1.html#tth_chAp1" target="_new">http://www.snort.org/docs/writing_rules/chap1.html#tth_chAp1</a>

Network Monitoring- Network Monitoring would be products such as snort that monitor the flow of traffic over the network.

Quick tips and tricks

<ul>

<li>When setting up wireless networks and access points there are a few quick steps that can be taken to immediately secure the network, even though it does not make it secure. Some of these ways include:

<li>Change your default SSID: each router or access point comes with a default SSID. By changing this it can take longer for an attacker to know what type of device he is trying to hack.

<li>Change the default password ? generic default passwords are assigned to access points and routers. Sometimes the password is admin. By changing this password, the attacker cannot modify settings on your router as easily.

<li>Disable broadcasting SSID: By default AP's broadcast their SSIDs, if you shutoff this setting it is harder for outsiders to find your AP.

<li>Enable MAC filtering: WARNING: this can only work in smaller environments where a centralized access list does not need to be maintained. You can enable only specific wireless cards to access the AP by only enabling those MAC addresses.

<li>Turn off shares: If security is important, scanning for shares and turning off the shares on the network can help. Also encrypting sensitive data can prevent hackers from accessing the data.

<li>Put your wireless access points in a hard to find and reach spot.

<li>Keep your drivers on all wireless equipment updated. This helps patch existing security vulnerabilities.

<li>Read current press releases about emerging wireless news.

</ul>

About The Author

Richard J Johnson

Network+ Certified

RJ Computer Consulting

<a href="http://rjcomputerconsulting.com" target="_new">http://rjcomputerconsulting.com</a>

Richard@johnsorichard.com