Reason to be in Safe Mode, when examined in the vaccine

True Find ahbaseuteu concealed set of diagnostic items. Concealed What is the diagnosis

? (Other vaccines will be happy if you are.)

 Rootkit virus detection technology that can conceal diagnosis that is. So here you have any questions

Going long., A rootkit What? The privileges of the root account of the attacker's computer administrator account rootkit

Consisting of a program that is used to obtain the kit (kit). Hence the name root (account) kit (kit) two

Together is called a rootkit (rootkit). Rootkits that are used in the other viruses, rootkits and other

Code and data within a computer system to hide most of the techniques and tricks of the main part. Is

When speaking, most rootkits to hide files and directories, and otherwise remote from the non-

Will that pose a threat to security, authorized access, network sniffing through. Vaccines Tom

Does not support. But this and what is safe mode? If you boot into safe mode, the primary driver

Load the server and start the program only after the start, is not it? Vaccine to detect rootkits

Is able to occupy a lot of cpu process will catch and run in safe mode.

Easier because there are fewer programs that are able to catch blood.. Rootkits, as well as other

All are the same for both viruses. Can catch better when running in Safe Mode.

Editorial Design

To edit the manuscript book is created through several steps to ensure that hwaljahwa. Editorial Design Editorial Design of printed materials such as newspapers, magazines, books, able to make a good visual editing the manuscript. In other words, book design Book Design, Publication Design (Publication Design). Manuscripts, editing, printing process, from planning through to deploy until the public says the entire process.

Editorial design history
Overseas: The editorial design history of a close relationship with the magazine's history. Magazine in the 1890s, the United States already widespread being. However, the concept of editorial design can be visually edited in the 'Fortune' in the 1930s introduced the concept of design to start.
Domestic: the case of Korea, the first magazine was launched in 1976 in the 'deep-rooted' tree art di suppression system LE was introduced. In particular, the concept of the grid by applying new visual order presented by the magazine, of course, had a huge impact on all publications. Of typeface development and typographic research and the most effective way to be able to pass a message to a lot of effort as well as the cover design nowadays is followed.

Editorial design (for example - Newspaper Design)
Editorial design
Prints and all you can see in our day-to-day editorial design. Furthermore, it is no exaggeration to say that had something to do with the field of visual design. Edit the design as a kind of Stars and issuance cycle for each type can be divided into two. In addition, depending on the size, thickness, and the binding manner breaks.
- Issued per cycle
Regular gahaeng water daily, weekly, monthly, bi-monthly, annual, etc.. Occasional gahaeng water: general poetry or fiction, such as books, corporate promotions and lesser.
- Type
Prints cut sheet (sheet): Chapter 1 DM, invitation, letter heads, business cards, etc., etc..
Spreads (spread): newspapers, catalogs, brochures, etc..
Shape: books, books, books and magazines.

Editorial design components
- Layout
Is one of the most important parts of editorial design. Says to place the contents of each array of features and visual harmony between each other, the plan or task. Herbert According to the layout, "their imprint in the ground and decorating ideas and forms a unique combination." Said. The plans and ideas, and is ready to meet the intent of the type of book or editing is required. Lineup with the layout of the elements (line-up), format (format), margins (margin).
Lineup (line-up): says that a good understanding of the contents of the book, each, depending on the content and importance to the array and split. Says the planned compilation of all, place them in the task of dividing ground.
Format (format): the size of the book, direction, number of pages, and the amount could be as simple as Means to design a realistic, cost-effective, taking into account the appearance of the book.
Upper margin usually telling the part of the border margin (margin): book of blank space inside and more catches. Margins, unless there is a specific reason, such as special intentions at all, or other content that consistency from beginning to end is the most Tells the beginning and the end of the main content, the margin gives attention performance comfort unity.
Typography (Typography)
To convey the message is the most obvious element of the editing design elements. This is closely related to the 'readability' and Makes the layout, font selection and size of the letters, typesetting format, character position, and the inter-line spacing, letter spacing, and the length of each line is good to be in harmony with each other.
- Font (Font)
Say the letters of the name of the typeface, which is also known as Usually the guy who invented or city name comes from the shape of features, etc., you can find its origins.
⇒ Hangul typeface: Gothic and mainstream Myeongjoche in the Roman style, including the Korea dongyanggwon most commonly used. Yunche, Dolce and fits in the sense of a new generation of font development lately has been actively performed.
⇒ size refers to the size of the letters: print, if the point (Point), photo typesetting 1st grade class is displayed as 0.1-point is about 0.35mm, 1/4 the length of one side of the character is a square.
⇒ 1 = 0.3541mm, approximately 1/72 inch
⇒ 1 class = 0.25mm
Grade point ⇒ change: water supply (watering points × 1.4 = / 1.4 = Points)
⇒ Thickness: the thickness of the letters says.
⇒ three (light): thin typeface says.
⇒ (medium): usually refers to the typeface.
⇒ state (bold): is a bold typeface.
⇒ dogs (extra bold): is very scratched typeface.
⇒ Height: Static (normal): refers to a standard typeface.
⇒ Condensed (condensed): congestion portrait of proportional typeface says. Longer than
⇒ pyeongche expanded condensed says congestion is longer than the horizontal proportional fonts.
⇒ slope direction and angle of the letters says.
⇒ body (vertical): average vertical perpendicular to the direction of the characters refers to the typeface.
⇒ carcasses (italic): diagonal slope in the font says.
⇒ character spacing (spacing): says that the appropriate character in the limited space of a certain size to adjust the position in the array.
Says ⇒ kerning (letter spacing):'s letters and letter spacing. Interval is presented in a visual and sensual rather than mathematical figures should be uniform.
⇒ spacing (word spacing): because each begins and ends with different shapes of letters that make up words, constant sensory to be seen should be. Should not be too bound about with grave cloths distinction or not, I was so nervous because it feels like a separate attached.
⇒ Leading (line spacing), the vertical spacing between geuljul and geuljul says. Often between the lines a lot to reduce the minus leading minus leading.
⇒ sort of characters varies depending on where duneunya that geuljul standards entire geuljul appearance. Centered, usually at both ends meet, fit the front row, the back row of matching is divided into four ways.
Front Row Fit
Centering
Back row Fit
Varies depending on where duneunya that geuljul standards entire geuljul appearance. Centered, usually at both ends meet, fit the front row, the back row of matching is divided into four ways
Varies depending on where duneunya that geuljul standards entire geuljul appearance. Centered, usually at both ends meet, fit the front row, the back row of matching is divided into four ways
Varies depending on where duneunya that geuljul standards entire geuljul look front row, usually at both ends meet, fit, centered, fit the back row of the divided four ways
- Cover design
Compilation of the cover design is full of images of a stool, because first impressions are very important. Typography, illustrations, photographs, etc., and also requires a deep understanding of the printing process and cost.

■ Print
- Bolrokpan Print
Reminiscent of the principles of print bolrokpan the most easy-to-understand picture of printmaking. Steeped up to the plate, geese Figure Roller shoots ink to paint on a piece of paper on the screen. In this print, the geese Figure calm, printmaker carved plate., Blood Printed Color ink saekjae printmaking paper, taking the hand presses can say. How to print (Plate) depending on the difference of printmaking in the corresponding part (plate) structure of bolrokpan reputation. Engraved, three are divided into bolrokpan principles of printmaking and the printed like ink and asking hwaseonbu spark does not ask precoders is higher than The principle of the woodblock print () is
- Flat Print
Means that the surface of the plate is flat. And sparking precoders hwaseonbu is on a flat surface, such as ink or engraved like bolrokpan asked hwaseonbu and does not ask sparking precoders divided by the surface of the concave, convex, not to put the tiling. Lithographic printing applies the principle of the repulsion of oil and water, the direct and indirect printing print. This principle is imagined by the state of the oil on paper when you drew the character or figure. It would have been a translucent oily. Sprayer then if the water in the entire paper ppum pristine water without the oily part of the moisture accept. In other words, the paper portion of the aqueous and the oily part is definitely something apart. In this state, the meteors are satisfied ink, ink on paper asks only part.
Water and oil, repel each other, the ink does not work, printing ink because it is the most meteors in the wet part. Spark reputation, the same principle as a sheet of hwaseonbu when Prepress lipophilic (亲 油性) and dashed into the hydrophilic hayeoseo make When printing, the ink on the surface of the plate is soaked in water once buried. Accept ink without the lipophilic hwaseonbu first stained water, the water dashed the plate made of hydrophilic spark ink is attracted and rejected.
Lithographic printing called offset printing, but, strictly speaking, is soon offset reputation.
Offset once the ink is not printed on paper plate in a straight rubber blanket (Rubber Roll) warriors (转 写) then printed on paper that is. Bolrokpan or engraved in, but sometimes takes an offset manner, most often reputation. And reputation in the field of commercial printing to print offset manner, called offset printing began to understand the reputation as
- Offset printing
General printing and color printing are widely used in posters, magazines, flyers, imprint color that contains a lot relies almost offset.
Merit
1) transcription and from the rubber blanket on a plate in the rubber blanket on a piece of paper to print the rough side of paper, you can print in color.
2) a zinc plate is the main sheet, and relatively inexpensive easily print larger sizes can be.
3) a fast print speed when printing many copies of that.
4) small print, such as trademarks, in larger sizes, simply by creating multiple editions multiple times at once, you can print.
Case 5) color, 4 wonsaekpan as six degrees of print, but using a complementary color gradation is weak, depending on the print print more than the print frequency can be added.
- Gravure
Is the most appropriate printing method for printing photos, because you can get rich gyejoeul. Particularly by the development of color gravure color printing even being used. If a good well-absorption of ink such as offset printing paper is available almost any blood, print, or printing paper selfish. Only blemish prepress rain too expensive if it is a disadvantage.

Features
1) the limitation of the paper is small. Requirements, but the smoothness of the surface, art paper, but also nice and flat to the surface.
2) a wide range of inks.
3) material other than paper, cellophane, vinyl, polyethylene, metal, wood, and easy to print.
4) production costs have shortcomings to offset costly than is the case, as shown above, a special print.
- Special printing
Addition to some way of printing, but three tiling tiling. Representatives to screen printing. Previously, literally called silk screen printing silk screen, but now use a steel or nylon net. Formal hearing is a kind of printing. The principle of trial and the old deungsapan. There deungsapan fed stencils seconds those seconds to peel off (or stylus) to write letters golpil bear the expression of the ink print. Screen printing stencils in that role instead of steel or nylon net. Net portion of the screen, and that made hwaseonbu non-conductive ink valve to the top of the screen to prevent the plate.

Linux desktop ecosystem players and non-profit activities

Foundation of the GNOME Foundation can be associated with the Linux desktop. Was established in 2000, the GNOME and the GNOME desktop project management. GNOME desktop, the 1997 Miguel de Icaza (Miguel de Icaza) began with a complete open source desktop. Each of these desktop of a graphical user interface is based on a core set of Currently, Red Hat, HP, Sun Microsystems, the participation of the foundation, and is extensible and provides a framework that can be integrated into applications on the GNOME desktop and desktop development guide.

KDE League as an organization to support the GNOME Linux desktop projects in addition to the project. KDE Linux desktop environment like GNOME project and provides project. KDE League and promotional activities for the KDE project focus has been operating.

On the other hand, the open-source consortium OSDL DTL (OSDL Desktop Linux Working Group) is pushing the Linux desktop projects. Participate in the project by a myriad of companies, Red Hat, AMD, HP, IBM, etc. This is typical. DTL main goal, not technical, and social barriers to be adopted for the Linux desktop that promotes the use of Linux on the enterprise desktop. Development by providing a portal role including international keomyunitieul Linux desktop for the Linux desktop community to converge together, and has supported ISV and developer.

They're pushing this as well as work together to set the standards, such as LSB (Linux Standard Base), ODF (Open Document Format), availability of applications for the Linux desktop troubleshooting and strive to have.

Provider of commercial open source Linux ecosystem kotop Death
Commercial open-source companies, such as Ubuntu, Red Hat, Novell / SuSE, Linspire (Linspire), (Uuntu). Red Hat, Red Hat Enterprise Linux (Redhat Enterprise Linux) of the brand and business products. Fedora Project launched by the end of 2003, are based technology that can be used in the product line development.

Novell Ximian (Ximian) in 2004, acquired SuSE Linux Novell Linux market creation strategies greet a significant turnaround and, in 2003, the new leader in the field of Linux desktop was injured. Support and also improve the usability of the Linux desktop, and Linux in order to promote the spread of the Nobel openSUSE Linux (OpenSUSE Linux) project. In addition to Ubuntu and Linspire is a good example. Linspire Linux Desktop, Linspire has released the sales Linspire products are currently being sold in more than 65 countries. School or corporate client base has
Canonical Ubuntu (Ubuntu) Mark Shuttleworth Mark Shuttleworth made from the Ubuntu Foundation funds raised through donated $ 10 million to progress, and product support and consulting services for projects that are on the knife. Ubuntu project is Debian (Debian) were derived from the server, but for the purpose of easy-to-use desktop version.

Strategic ISV of the Linux Desktop Support
HP is supporting the Free Standards Group (FSG), GNOME Foundation, KDE, OSDL DTL. Debian Debian project's infrastructure so that it can be used as an additional system, a lot of HP workers in Debian (Debian) develop and participate in the community, donations, and internal development platform. In addition, HP to sell Linux PC Linux desktop ecosystem for trying.

IBM Workplace Client for Linux strategy in mid-2005, is pushing the Linux desktop strategy. Like HP and Linux PC is manufactured and sold by IBM. Also supports Linux desktops, such as KDE, FSG's LSB, OSDL DTL-related projects, and promoting the project to establish the internal Open Desktop Open Desktop. IBM internal staff about some of the Linux desktop migration pilot operation're promoting Linux PC on the market potential of the experiment, it is known that

Package is Ubuntu package advantages

Will use the term package in Linux. So package What if I do not know.

Computer program is created by someone. Programmer can call me he.
Programmers will be written using a computer programming language. C or C + +, a lot can be used. However, we often called source code written in C or C + + program is simply a text file.
So I will be a source file, the executable file, the executable must be built through the compiler, assembler, and linker.

Run the executable file will need the support of the library. But is that libraries who need to run as a build-time. This Windows or Linux's true

Depending on the Windows version of Windows, if a company is created and maintained because the library does not change significantly. So the Windows side, while a good portion can be seen as one.
If you build the executable file in the Windows environment Windows environment where viable features.

Linux, however, if a little different. Being made by the various library is different, depending on the version of the kernel,
Does not guarantee that an executable file to build the library, depending on the environment, and to rely library version differs run.

So, get the package, the concept of these distributions fit the environment to build the executable file compressed.

Corporate position in the source file when you sell that 2007 for Linux English, because they may be reluctant to disclose the form of an executable file to distribute the package to distribute the files together.

The advantage of the package focused environment without the need to compile the advantage of being able to install because it is already built.
Of course, there are also disadvantages of the package. It is just that when you install this package, should be the same as the build environment. Be required to build the library and a compatible version already installed. This is a dependency package.

Package approach initdefault rpm and Debian deb series and so on.

Installed using the package in a way that does not is a way to compile and install the source files directly.
Difficult to install than the package, that's why this compilation goes smoothly, but
Intermediate environment differs errors users need to adapt. And take a long time to install because you need to compilation's.

Why not Debian, prefer doeneunya Ubud-to-excellence because of the package management system.
That way Debian package by package maintainers are managed through the network to download the package in the package when dependency checking package dependencies and their environment if it is not installed automatically help you as far as you can install the package dependencies and can.

Ubuntu apt or dselect command to search for packages and to download the Synaptic Package (package of Korean) will be replaced with graphical interface. That is the same thing, and were down search or a search was apt to Synaptic Package graphical environment or command value difference - eat.

Ubud Altoona Debian package from the network to download the URL needed it in the / etc / apt / source.list address. So there more recent material, source address to the list, add the new address came a new package down will receive. Primarily from individuals or organizations to deploy the package because the address is endless, but using only the official site or mirror site.

Version of Debian was Ubuntu, which was to exist, and exist to deploy this version whenever you Nickname.
And full version does, in fact, in testing or unstable development version, you will be attached.

Will be the address to be added to the source list carefully, because the environment is different, depending on the version.
We recommend that you add to the list of sources in the environment, so that the same distribution.

Network file / printer sharing

Devices are connected to the same router, or hub connected to the unit depending on the configuration, such as a network file / printer sharing.
In order to share with your network, check You will find below.

1 Please check the working group are different.
Start -> Control Panel - Classic View - go into the system - computer name - change the workgroup, and check for equality hoc working group or the English or the number connection it may not.
As the name must be different, but also the name of the computer must be alphanumeric.
There may be a problem in the case of Hangul Compatibility

2 Make sure that the underlying protocol is
Start - Control Panel - Network Connections - Local Area Connection in the installation if you are the right mouse button - properties - Installation - additional protocol - Microsoft - NWlink
This section is part of Windows XP.
Does not apply to Windows Vista or Windows 7.

3 Make sure you are connected to the same router.
If the wireless signal that is connected to the other, sometimes.
Start - All Programs - Accessories - Run - cmd pressing instance of MS-DOS window (or the case of Windows 7, Start - All Programs - Accessories - Command prompt ports)
appearing gateway by pressing the ipconfig all computers must have the same address.

4 Start - Control Panel - User - Make sure that the Guest account is activated.
Windows 7 Start - Control Panel - User Accounts and Family Safety - User Accounts - Manage another account - change the Guest account must be

5 Start - Run - cmd - IP address from ipconfig you back to confirm.
Check If you start - run - cmd, and then launched a ping to the IP address of the other party (or Start - All Programs - Accessories - Command prompt in Windows 7 port) # # # # # # # # #. # # #-t to enter your test please ping out.

6 (If you want to share the printer), it is very important that you are pressing the right button and select Start - Control Panel - Printers and Faxes - Printers properties - port - port configuration settings by pressing the corresponding IP.
Most printers connect to another computer, in Control Panel, Printers and Faxes option from automatic to search automatically finds.

7 ) If you want to share files (Windows Vista or Windows 7, Start -> Control Panel - Network and Sharing Center, part of (Windows 7) from a password-protected portion of the advanced sharing settings and turn off the option to share the network, such as the ability to search for files must turn.

8 Now press the right button and select the folder that you want to share and click the share options, please share.

If you do this, most of the connection will be completed.

Xen Solutin? Open source-based virtualization solutions

XenServer Virtualization Hypervisor need to build. And that's associated with it Hyperviosr role XenServer ... When the place of these Server on top of XenServer Service Desktop Virtualization Server Virtualization, Virtual Machine (VM) If you make a place Service will
Infra build cost compared to XenDesktop XenApp Application Virtualization Only specific Application Publicing area delivers to users the way it is, and has been deployed on a central server, Application Service architecture where multiple users at the same time as it enters the relatively small. I would need when you want to use the Service and Special Application ..
XenDesktop - you're well aware, the desktop virtualization space slip ... Earlier mentioned Hypervisor ... The user to configure the Desktop Delivery Controller for XenDesktop is on XenServer OS (desktop) Delivery solution that is Infra build need to assign a per-user CPU, RAM, DISK, etc., because of the relative cost to enter, but ... Do not provide the same environment, and the use of the actual PC ..
XenClient -'s been made by the special needs ... Industry's first Client virtualization area think that if you are XenDesktop and the biggest difference between ... XenDesktop been configured on the server, and Service ... Approach should be to use the Network to volunteer ... Network does not, you will not be able to receive the service. Even on Offline such use but XenClient were picked've created for the sole purpose of ... Centrally managed virtual desktops in the corporate PC and laptop can run allow ... Online Award in catering the Syncronizer synchronized with a central server .. Offline day when ... Client PC / Laptop of Resources is being used by the virtual machine to use. Easily be described ... Tear down the laptop ... Guy to install the XenClient Hypervisor can play a role in Is that if you install your virtual machine you wish to use and then later ... Synchronizer and synchronization to synchronize with the central server Online / Offline guess if all virtual desktops can be used.
Intel vPro hardware virtualization (Intel ® vPro ™) technology and integration, and architecture through the bare-metal (bare metal) the highest levels of performance, security, and separation (isolation) gives Xenclient Owned laptop as their personal virtual desktop through desktop virtualization technology to provide expanded other words, many users can provide a more flexible and enhance the user experience in the user's local notebook to provide a virtual machine-based desktops and portable one more freely than their local desktops or applications that allows you to install and use the terminal and used in the industry, provides a central business desktops, geotyijyo ..
In short, users who come • Provides Mobility Please enable efficient work and on the offline IT administrators to provide control and security features that are required in the corporate notebook that allows you to enjoy the ease of central management technology.

The pros and cons of Optical Fiber

Chapter points



1 Is a low-loss, broadband.

Enables low-loss telecommunication repeater number and hence reduced.
Transferred meurosseo broadband are increasing the number of channels.
When comparing the degree of attenuation depending on the frequency band fiber look 0.2dB/km (1.55um), 0.35dB/km (1.35um).

If 22.6dB/km such as coaxial cable.


Compare the bandwidth, the available bandwidth of the optical fiber is approximately 30THz 500MHz Twisted pair, coaxial cable is 2MHz.


2 Compact lightweight.

When comparing the diameter of the optical fiber's core diameter 10um (single-mode), 50um (multi-mode) and the cladding diameter of 125um coating diameter 250-500um.

Will thus have the largest diameter and the diameter of 675um there has

600 sim cable outer diameter: approx 42mm

Of the coaxial cable outer diameter: 28.4mm

Weight when compared

Optical fiber: 6kg/km

Coaxial cable 1110kg/km


3 Electromagnetic interference (EMI) is irrelevant.
Light signals, electromagnetic waves does not occur.


4 Is electrically protected.
UA and ONA is not about sending and receiving signals of the light because of electromagnetic waves around.


5 Of signal interference does not occur.


6 Has a long service life.

"Fiber-optic: 20-50 existing cable (12-15)"


7 UA and ONA temperature of cable compared to less corrosion resistant,.

In fiber-optic cable, but requires the co-ground co-grounding is not required.



Single point

1 Expensive maintenance and repair costs.

Time-consuming and too high maintenance for equipment go so much in the domestic has not.
For example, usually the middle of the cable Fired jyeotdamyeon easy to find those parts.
And is that part just after simply
To find that part in the middle of the fiber-optic fired, if it expensive to find parts and equipment if you would like to connect another optical connector using the equipment that you need to connect.

2 Equipment is required for optical signal modulation.

Existing cables, but complex enough to not be compared, cable and fiber-optic cable, such as demodulation and modulation modulation through the process tend to be rather large because the equipment.
Was more than the advantages and disadvantages of fiber-optic cable.

Needed to build a home network equipment

If you want to build a network, such as LAN cards, hubs, UTP cable and equipment is needed. To branded products from Taiwan expensive 2Com, Intel, HP, etc. These network equipment is affordable are sold at various prices. But, if intended for use in the home, you do not need any expensive equipment to prepare.

NIC (LAN Card)

Is a device used to connect your computer and other computers. When you purchased your computer, If you did not order, separately asked to install a network card NIC is not to configure your computer, including basic equipment. To connect the computer to the network, all the computers on the LAN card you purchase and install must. 10000-30000 won enough computer parts store in the Yongsan Electronics Market is available for purchase.
Adapter, depending on the type of connection with the main board of the computer (motherboard), PCI and ISA way way way divided, ISA Nowadays, almost does not use older computers unless a fast transfer rate of PCI-Adapter buy. Way of a credit-card-sized PCMCIA notebook computer must be equipped with a network card.

Hub (Hub)

If hub is required to move data from a computer network, which acts as a conduit to connect to the computer for more than three If you compare to broadcast a computer network can be related to the headend to the hub. In other words, a device that acts as a link between the NIC and the NIC is the hub. Called holes to connect the computer cable and hub port (port) ', the difference in price, depending on the number of hub ports will Be added later on the computer network, especially if you consider that it is recommended to buy a hub ports are now grouped into a computer network than four or five connections, the more

UTP cable

UTP cable to connect the NIC and the NIC, the NIC and the hub is a communication line. Aisle and from the data on a computer network that would be UTP cable and serial cable (Direct Cable) Cross Cable (Cross Cable) is divided into Cross UTP cable by crossing the wires to be used for sending and receiving the cable to connect two computers directly to 1:1, ie, a direct connection between the NIC and NIC if using. Network to connect three or more computers, a serial UTP cable to connect the NIC and the hub, and the hub in the middle.

Home network technologies

Aimed at the home LAN technology


1 Home PNA

As you can see, he stands in the Home Phoneline Network Alliance (PNA) is to build a network using a telephone line wiring is already in the house. Area using some of the phone line for voice signals to pass, because still has the disadvantage of staying at a slow speed of about 1Mbps. Simple level of network does not become a problem, but is about the HomePNA specification 2.0 10Mbps transfer rate level raised. Daisy chain (daisy-chain) in the form of reduced wiring complexity is thin compared to the LAN cable connected to use the telephone line, so installation is much easier.
Expensive, but compared to the transfer rate limits and general LAN card very popular not do. Apartment complex, home networking, rather than a kind of high-speed communication, etc. ADSL B & A, primarily being used.
) Daisy-chain concentrated in the hub, rather than the star-bus topology and connection string as the complexity of the wiring in the form of much less.


2 Powerline network

Technology came from a similar problem with the phone line consciousness. Difference between a telephone line instead of using powerline najiman power outlet is not coming because there is much less difficulty of wiring. Competitive compared to ADSL, but fall in the home network is simple to build and information in consumer electronics, high-speed communications, from the simplicity of the network connection when power lines have many advantages. Dissemination of the telephone line is not made, the developing countries have a fairly large compared to other high-speed communication advantages. Home information appliances alone without any other connection cable outlet in the building of home networking is possible, especially strengths naesewoogo.


3 Bluetooth (Bluetooth)

'Blue-tooth' unusual name of this technology, is one of the leader of the next-generation network technology. 10M within devices that connect at speeds of up to 1Mbps Bluetooth technology that tie in to the PC and laptop, cell phone, PDA, portable devices such as wireless access technologies. It is comfortable and fast synchronization of data between the growing portable devices and data transmission so that you can aim. Off devices or RF to infrared, unlike commonly used until now because even if there are no obstacles between the communication is possible. As the Bluetooth SIG (Special Interest Group) of Ericsson, IBM, Intel, Nokia, Toshiba, and exhibitors only evident technology is the world standard length solid polished. , However, have impeded the commercialization of thing did not become as cheap as expected, the price of the module.


4 HomeRF

Bluetooth and a little different from the field, but rival in the wireless network technology. As the name implies, in the home network, using an infrared non-RF approach take hold of the targeted building. Plans yet somewhat slow 1-2Mbps of speed, but not only to the new standard in the class increase the transfer rate of 10Mbps. Between Bluetooth and WiFi camp, but struggled to find their place, the direction of the future, depending on whether to allow the FCC in the new price is expected to be decided.


5 802.11B / Wi-Fi

Currently basing most of the high-speed wireless network products in Wi-Fi. 11Mbps class this group evolved from existing 2Mbps standard naenoteun products are already being sold in the market. Screen in the most pragmatic camp in the surrounding wireless home networking for now ahead of the group. To configure the network through several companies product mix compatibility certification guarantee is provided.


6 IEEE1394 / HAVi (Home Audio Video Interoperability)

Somewhat different from those of several previous groups, but the field may also be referred to as, ultimately, is competing in the home networking. 400Mbps to faster transfer speeds and plug-and-play, hot plugging supported significantly ahead of Apple in the development of the current IEEE1394 bus. Until now mainly use digital camcorder and video editing devices, etc. have been to transfer multimedia data, seems to occupy a large proportion of excellent points, thanks in home networking. MS of 'Universal Plug and Play (UPnP)' and the line 'Jini', over the place of the standardized wage a fierce quarrel seems

SNAT and DNAT

SNAT rule in NAT devices in the outgoing packets that meet masquerading (masquarding) and SNAT (Source NAT) is a similar concept as masquerading and SNAT outgoing packets via NAT devices to change the source IP address with the specified IP packet If the NAT device changes the source address of the packet to a predefined IP. usually the source IP NAT device's IP address can be used.
How SNAT works through an example let's look at the network configuration below will be assumed equal.

                     (SNAT installation) + --------- +
IP: FWEXT | eth0 eth1 | IP: FWINT
- + --------- / / ---------------- | | ----------- + ------ ---------
      External network | | |
+ --- + --- + + --------- + + ---- + ----- +
| | Firewall | |
| | | |
+ ------- + + ---------- +
Web server (IP: EXTWEB) local PC (192.168.1.1)
GW: FWINT



SNAT is set in the above network configuration on the firewall if you do not, the local PC can connect to an external web server. Local PC's IP is a private IP can be routed over the Internet and private IP because If SNAT is set in the firewall, the story is different. SNAT how the local PC so that you can connect to external Web server, let's look at how.
Send the packet to the local PC to connect to the external Web server. In this case, the packet's source IP 192.168.1.1, and the destination IP will be EXTWEB because it is assigned to the local PC's default gateway FWINT packet is forwarded to the firewall. Firewall packet through the normal routing process external interface passed. configuration As you can see from the firewall SNAT external interface is set. exit just before the packets on the external interface, the source IP of the firewall external IP (FWEXT) to change is come true. (SNAT routing after careful let) after the packet will be passed to the web server and the destination IP packet is received, the web server if you send a response to the packet source IP EXTWEB will FWEXT a Web server's response packet, the firewall being forwarded to the firewall will see the source IP, source port, destination port information SNAT that was this packet is a packet of response, so the firewall 192.168.1.1 source IP FWEXT to change after (the process of de -SNAT) is called routing, and finally the packet is forwarded to the local PC. Local PC and an external Web server-to-server communication in this way that would be possible.
More information, implemented using the iptables is as follows. iptables-t nat-A POSTROUTING-p tcp-o eth0-j SNAT-to-source FWEXT
                                      DNAT is the opposite concept. As its name implies, the DNAT to change the NAT device as the incoming packet's destination IP address. Usually have a server on the local LAN, and does not inform the external server's IP for load balancing purposes or to be used for through the same example above and let's look at The configuration of the network to be used in the description as follows.

  + --------- +
IP: FWEXT | eth0 eth1 | IP: FWINT
- + --------- / / ---------------- | | ----------- + ------ ---------
External network | | |
+ --- + --- + + --------- + + ---- + ----- +
| | Firewall | |
| | (DNAT install) | |
+ ------- + + ---------- +
External client (IP: EXTCLI) local web server (192.168.1.1)
GW: FWINT


As the actual address of the Web server configuration, as can be seen in FIG. Using this IP 192.168.1.1, but can not communicate with external clients private IP because routing rule does not Therefore, the Web server should look as though you are using a public IP on the outside. For this purpose, the name, the address of the web server on the server can be set to FWEXT on the Web server you want to connect to an external client eventually the FWEXT: 80 packets to send. Firewall receives the packet. Firewall to decide whether to allow the reception of this packet is received is determined by the DNAT changes the packet's destination IP address to 192.168.1.1. Thereafter, the routing process, the packet is to go the internal side of the firewall packets from the external client interface to be delivered (DNAT is done before the routing) that is passed to the Web server so it is passed to the Web server. Then, the web server sends response what happens? The web server will send a response to the external client (EXTCLI). That the local IP of the web server rather than the default gateway FWINT because it is set to the response sent by a web server eventually passed by a firewall is a firewall DNAT check the received packet information such as destination address, destination port, the packet learns that a response that was packet, the source IP of the packet to change their IP (FWEXT) to be (this is called de-DNAT) after the packet is passed to the client through eth0.

Or more, using iptables as follows: iptables-t nat-A PREROUTING - dst 1.2.3.4-p tcp - dport 80-j DNAT-to-destination 192.168.1.1
192.168.1.1-10 local web server load balancing effect 10s If you want, the above is as follows: If you change the rules. Iptables-t nat-A PREROUTING-dst 1.2.3.4-p tcp - dport 80 -j DNAT-to-destination 192.168.1.1-10
This round-robin load balancing is possible. Tenth client traffic sent first sent by the client traffic will be forwarded to the 192.168.1.1 to 192.168.1.2, the second sent by the client traffic is being passed, the traffic sent from the client to the server 192.168.1.10, the eleventh being forwarded to the 192.168.1.1 expression is

RIP and IGRP

-RIP
Routing protocols, dynamic protocol. Used to diseuteonseu vector algorithm is a protocol for internal use.
How to choose a good way HopCount up to 15, and the update period is 30 seconds.
Use Disadvantages: reliability, line speed or line of road, etc., not only rely solely on hop count, so
* Set the line speed using V.35 cable Clockrate deeper.
Information sent from RIPv1 to understand, regardless of the version, but the information sent from the RIPv2 RIPv2 can be understood only in
Default Distance value is 120
RIP configuration commands
  - Router rip
  - Network network-number

Administrative distance values ​​are different protocols from which routing protocol to use path information
Find how? That value.

-Distance Vector routing algorithm of the problem and solution
Problem: time. Passed to the routing table once learned, the time updates are delivered to all network
  (Convergence Time) looping occurs often say a lot of hanging.
Solution
  : Maximum Hop Count used. And 15 is determined by the maximum number of hops over a value is considered as unreachable
Flush Time after Sikkim deleted. Problem .. Can not use the path hop count beyond 15
  Use: Hold down Timer. Notifies you that the network is down, the router in the network is down for the start Hold down timer. Hold down timer that operates during the routing path information received from the external metrics such as Hold down the count had terminated or a new path to the destination if the good or ignored and update management.
  : Split Horizon. Where they are coming from the routing information, the same information can not be exported. Made the entire network using only the roofing of the two routers to prevent difficulties in
  : Route Poisoning. Infinite metric value of the network is down, the router learned that the network is down, replace the
Unusable mandeum. Are erased from the routing table can stop the wrong routing information.
  : Posion Reverse Split horizon with poison reverse update. Carried out if the update by sending the value of the Send but can not use infinity, infinity hopgap not be split like routing information sent nSubmitting routers if by mistake the wrong path information used to significantly reduce


-IGRP
Routing protocols and dynamic protocol. Routing protocol is intended for internal use, diseuteonseu vector algorithm is used. Algorithm invented by Cisco, and Cisco can be used only Path decision
  : Bandwidth (Bandwidth) - interface serial 0 bandwidth 56 (56kb as set) Default 1.544Mbps
  Time to get through the path: delay (Delay) -
  Shows the figures: reliability (Reliabilty) - to send packets through the transmission medium, and the resulting error rate
  Hanging by a certain amount of load: Load (Load) - on the path to the origin and destination, whether measured
  Maximum transmission unit (MTU: Maximum Transmission Unit)
Every 90 seconds to update the routing table. Maximum hop count of 255.
Disadvantage as RIP and classful because do not support VLSM (Variable Length Subnet Mask).

IGRP configuration commands
  - Route igrp autonomous system numbet
  - Network network-number

Types of Linux distributions

Choosing a Linux distribution for beginners guide

Mandrake Linux





Started developing distribution Mandrake Linux Gail Duvall appeared since the beginning of July 1998
Has attracted immense popularity. Importing a Red Hat distribution, KDE as the default desktop developers change
By adding easy-to-use installer for Linux is difficult to install stereotypes changed.
Mandrake's hardware detection disk partitioning utility and millions of people the best in the industry
Regard. Ensure that as much convenience for many users to use the Mandrake OS
Says that


Mandrake Linux private users looking for a user new to Linux and alternative operating systems
Has been popular among Mandrake's development is entirely open and transparent.
New package directory in the 'cooker' is coming up almost every day. Enters a new release is in beta stage
Cooker snapshot of the first accepted into the beta. The beta testing process is usually short and intensive, but
Version 9.0 Starting with a somewhat longer and became thoroughly. Beta mailing list (much more than the bottom of the market ^ ^)
Crowded streets, so much for reporting bugs or other response is very fast.


The development of this approach eventually gave birth to release the latest version of Linux has been updated to date very quickly.
Distribution. Fairness, buggy than other distributions may feel somewhat unstable.
Many people have reported that these are acceptable levels. (Ultra) for the latest software
They ascribe when occasional applications to (^ ^) enough to endure the level of the
Will

Advantages: user friendly, graphical setup utility, tremendous community support, NTFS partition size adjustment support

Cons: There was a bug in some releases. The first public release of Mandrake club members.

Software package management: RPM
Free download available, some time after the

Recommended variants: PC Linux OS

Homepage: http://www.linuxmandrake.com http://www.mandrakesoft.com
Nationality: France



Red Hat Linux and Fedora Core





There are a lot of people immediately think Linux Red Hat named to hear. The most famous in the world
Does a Linux company. 1995 Bob Mark eowing entrepreneurship spirit Red Hat recently, only the surplus structure to
Yiranda turned to the news service, and Red Hat Enterprise Linux product line, thanks. Now
Red Hat Linux 9 Red Hat Linux product line has become in the last version. Its consecutive impacts to the
Fedora Core, published in the second half of 2003. Officially under the auspices of the Red Hat Fedora
Community and participate in the development of the short-lived, mainly testing for Red Hat Enterprise Linux
And serves as a base.


What are the major characteristics of Red Hat Linux and Fedora Core? A number of in-house development of knowledge-intensive
Over the utility of the package and the latest conservative package with the perfunctory model is somewhat strange.
These packages, so that is not the latest version. If the new beta version, except security updates
Version of that package is frozen. As a result, the test tough enough stable distributions.
Multiple mailing lists and bug reports to the beta program, the way is open to the public.
Red Hat Linux server On the dominant distribution in the world was.


One of the reasons why Red Hat was the success of the various services provided by the company considerable popularity
Drag has Software packages via the Red Hat Network can be updated easily and free
Software Library and valuable information. Various types of support services and Enterprise Linux
Products can be purchased from Red Hat is not always cheaper, but if you need a highly skilled support
From the workforce can be a great support. The company even developed a certification program of its
Further boosting the popularity distribution of RHCE (Red Hat Certified Engineer) courses and exams, the current worldwide
Is available here and there. Due to these factors, Red Hat is now in the IT industry, that's what
Was able to stand as a brand name.


Advantages: The user base is wide, great community support, many of the innovative

Cons: the free edition of the product life is short, Danny multimedia worry about support on Red Hat Fedora with previous

Software package management: RPM

Free download: Can

Homepage: http://fedora.redhat.com/

Nationality: United States of America


Debian GNU / Linux





Completely non-profit project started in 1993, Ian Murdock, Debian GNU / Linux free software movement
Started close to the most in more than a pure model. Hundreds of worldwide developer voluntarily
Distributions basing participation and high-quality, well-managed and well-regulated standing
Is


Always, there are three sub-directories in the development process in the main directory tree (stable, testing, unstable).
The advent of the new version of the package for the first test goes into the unstable directory. If you pass the first test
Months to go beyond the testing directory, the package goes through a harsh test for This thorough
Tested and then less stable judgment. As a result, this distribution being the case, the most
Action must not have the latest version of reliable and unreliable point disadvantage. stable version
Testing for mission-critical servers, but many users on their own computers version or
like to use the unstable version.


Debian installation is difficult, one for a while or were known. Computer hardware for the
If you dont know erudition makes me atjiman. Apt-get something that complements this Debian package is convenient
Installer that can be installed. Future updates, you can use the apt-get utility.


Advantages: 100% free, great website and community resources, sufficient testing, apt-get using a relatively
Software installation is not difficult

Cons: old Fox Run installer, stable version of the old version (?)
Software package management: DEB

Free download: Can

Homepage: http://www.debian.org

Nationality: Earth (^ ^ ;)


Gentoo Linux





Started by Daniel Robbins, Gentoo Linux in Stamford (Stampede), Linux and free BSD
Development is one Gentoo BSD for a producer of pre-digging is the result of the auto-build
Function is referred to as the ports. Producers ports in Gentoo portage under the influence of this in the name of
Integration. Tangled story in the early days of Gentoo
Can be read here (in English).
Gentoo's first stable version was released in March 2002.


Gentoo, a source-based distribution is the only one in this list. Installation media, the various levels of pre-compiled
All the sources of the underlying ideas to help the basic Linux system operating on Gentoo binary package
Compile the package on a user's computer that will By doing so, the biggest advantage you can get
Is all the software that is highly optimized computer architecture. Also install software
Ends by simply typing the command to update to the new version, which is stored in a central repository
Software package is usually held to be the most up-to-date. Installing Gentoo on the other hand, then the latest
To be quite fast graphical desktop, multimedia, development tools, including proper distribution
Enough to take a few days or so tedious aspects in the computer.


Advantages: relatively effortlessly individual software packages you can install the very latest version,
Can enjoy yourself each system to meet the needs of their own to create the mood 'bizarre'

System installation, Disadvantages: long and tedious sometimes unstable and break down the risk

Software package management: SRC
Free download: Can


Homepage: http://www.gentoo.org
Nationality: United States of America


SuSE Linux





Defensive company focused on the desktop, enterprise-class products, but also sells. Suse
Thanks to the developers. Installer and the YaST configuration tool, this distribution is getting good reviews.
The documentation that comes in the box products, meticulous and perfect enough to be useful. Distributions in Europe and North America
Accounted for a significant market awareness in Asia and other regions, but not so high mothada. SuSE
The second half of 2003, Novell was acquired by


Suse developed entirely in-house, closed public beta test for development and does not provide.
In addition, the boxed product on the market, falling as long before my next spread a policy that supports software download.
ISO image that can be easily installed policy does not provide a user with the package of its
Are induced to purchase the product box.


Pros: professional package management, convenient YaST configuration tool

Cons: In some areas, there are not many users, resellers can purchase in some areas may not be
FTP install (IMHO), must have a reason (proprietary) components are, therefore, difficult redistribution.

Software package management: RPM

Does not provide a free download: Downloadable ISO images. But the Professional Edition
Can be installed via FTP, usually one or two months after the official release. FTP installation is not difficult, but
Broadband connection is required.


Homepage: http://www.suse.com
Nationality: Germany


Furnace fixes





Germany's Klaus furnace spurs the development of the Debian-based Linux distributions as standard level raised
Hardware auto-detection feature evaluation, I've been getting quite a bit of commercial Linux distributions, even
Shame makes Boot there is no need to hand write amazing, a huge software package, decompression speed,
Install the package on your hard disk, such as the ability to put tools into the ranks of the furnace necessary fixes.
Can be used to create a recovery disk, and show people you've never around Linux
Purpose is fine, too, free test before you buy a new computer for good. Even everyday
To transact business with a feature-rich Linux distributions may also be used.


Fixes the new version of the furnace, which often release comes one usually every 1-2 weeks.
Updates from the unstable branch of Debian bug fixes and the latest software packages
Perform the import.


Furnace fixes from the Linux media has been a wide range of lighting. The list of related articles, here's no fix
Spurs and interviews with Klaus furnace can be seen in the page, please consider In addition, we provided on LWN.net
Knoppix - Do not miss the Great Linux Advocate.


Advantages: excellent hardware auto-detection, can be run directly from the CD without a hard disk installation, repair tool
May be used.

Cons: run directly from the CD, the slow speed and performance.

Software package management: DEB
Free download: Can


Homepage: http://www.knoppix.org/ (German), http://www.knoppix.com/ (English)

Nationality: Germany


Slackware Linux





Patrick Volker Ding since 1992 started to build Slackware Linux is the oldest Linux distributions
Is still alive. Not too flashy, still insist on the text-based installer, and without graphical
There is a setting tool. Painstakingly other distributions to use for a lot of common utilities
Easy front-end development during Slackware convenience and is still far from everything
File has been processed. For these reasons, Slackware Linux usage rather grow up, even if the original intention
Elaborate attitude to learn and I recommend it to people who are


Nevertheless, Slackware still has the charm to attract many users. A high level of
Server stability and security because it has introduced is a good fit. Experienced Linux administrators,
Slackware package that features the most extended part of the original form, and self-development is much
Says relatively little bug because Naturally, the chances of bugs that many self-developed
That there is a high probability. Release, followed by the official release once a year, so not a very frequent side
Always up-to-date packages can also be downloaded. You want to look a little more deeply inside of Linux Slackware
Distribution is great for people.


Features: I heard distribution of the maximum. Your Linux box If you are having problems with your Slackware
Find the user. Does Slackware users to its ability to fix the problem than any other distribution users.


Advantages: a high level of stability and fewer bugs, and the closest to the spirit of Unix distributions.

Cons: all the settings way to edit text files, automatic hardware detection, somewhat falling behind.

Software package management: TGZ
Free download: Can


Homepage: http://www.slackware.com
Nationality: United States of America


Lycopene lease Desktop / LX





Leader prior to departure as Redmond Linux Laico lease was Joseph Cheek is the company's
CTO has the power to care and has worked for Microsoft, Linux and Prior. The intent of this distribution is
Distribution made easy-to-use Windows-to-Linux users move effortlessly scavenging
To be able to achieve the purpose of having. Lycopene lease Desktop / LX to achieve this objective
Extort high for numerous whistle in 'My Computer' or 'network neighbors' as well as Windows
Attractive default theme, XP and spitting. The current distribution based on Caldera OpenLinux
Is based.


Laico lease desktop / LX package is not so much a number, usually a business application
Policy, and taking one for general system administration control panel. Some critics package
Long been telling their developers say they improve the user-friendliness of their main goals.


Similar design advantages: novice-friendliness, and Windows

Disadvantages: Some old commercial version of the package, the per seat licensing policy

Software package management: RPM
Free download 45-day trial


Homepage: http://www.lycoris.com
Nationality: United States of America


Xandros Desktop





Xandros Corel Linux was derived from. Linux Corel Linux for the public in 1999, while attempting to
Seemed to be successful, but how much the company behind the financial crisis ended up stranded awesome ppajimyeonseo 0.2001 years
October 2002, the first librarian Jan. draw Suga distribution Xandros version
Announced.


Xandros Desktop, without a doubt, the current distribution for the first time on the market and most users familiar
Is highly recommended for people who use Linux. Number of applications contained in this distribution is much
But the developers are confident that the perfect job. Xandros package itself only to provide pretty
File Manager and other reasons, among them components. Are two kinds of plates, Deluxe (U.S. $ 99 fire)
CrossOver Office Standard (U.S. $ 40) The only difference is that the plug-in (Microsoft Office and other
Layer, so that you can run on Linux, Windows product compatible), NTFS partition resizing tool
Cheap version (Windows XP users) are missing.


Advantages: design, suitable for beginners, all in one box solved the great file managers, and other useful utilities.

Components Disadvantages: Some of the reasons include the redistribution difficult, free download provides not.

Software package management: DEB
Free download: No


Homepage: http://www.xandros.com
Nationality: Canada



Linspire (formerly Lindows OS)





Linspire (formerly Lindows.com) MP3.com founder and former CEO Michael Robertson in 2001
The United States in October in San Diego, started the goal to the initial distribution of Linux applications, as well as MS
Creating a major Windows applications such as Office that can be run from a Linux-based OS
Was. However, his ambition to have underestimated the tremendous effort to achieve its goal of entering
Was abandoned after


Lindows OS reveals itself in front of the public for the first time in November 2002 was the name Lindows 3.0.
The main features of this product is a quick and easy installation and click aenreon (Click-N-Run, the company's software from the pool
Is an easy-to-use Web-based infrastructure to download and install the software). Evaluation for this product
Varies. Click aenreon still seems to be a catch to Bug. The company's massive marketing offensive
Succeeded in planting the occasional unobtrusive and Linspire (Linux) in the mainstream media.
Linspire preinstalled computer products are sold to the United States, Britain, and Japan, and other countries in the current
Is


Advantages: design, suitable for beginners, quick and easy installation, one-click software installation.

Disadvantages: quite expensive, the software uses a pool of the annual costs charged

Software package management: DEB
Free Download: Lindows Live.


Homepage: http://www.linspire.com
Nationality: United States of America

Red Hat Linux

Red Hat Enterprise Linux scalability and Features
Korean Red Hat has already received recognition from many companies emerged as a new alternative backed by the world's leading companies, including IBM, HP, Unix and Windows, Red Hat Enterprise Linux AS 3 through retail stores has become. In keeping with the Enterprise Server kernel and stabilized a wide range of hardware support, and bear noticeable within large corporate databases and the advantages of reliable operation in mission-critical environments. ISV applications with the support of many more companies and also the migration of various applications are possible.
Installation CD 4 and unpacked source code, Chapter 3, Chapter 1, the document that contains the IBM Java add CD Chapter with the name tarun Red Hat Enterprise Linux AS 3 is comprised of 9 chapters. Hangul installation guide, registration card, license and certificate are included. Different depending on the version of the 2.4.21 kernel version of Red Hat Enterprise Linux AS 3 and maximum 16CPU, support for 64GB of memory.

UI maintain existing Red Hat
MS's product lineup as well as for the general user, the workstation from all systems in the enterprise using the Red Hat Enterprise Linux AS for mid-range and high-end server edition until the edition can be configured with Linux. This suggests that a unified enterprise IT environments can be built, and it advantages that can not be dependent from MS anymore and using a number of open source software in the enterprise IT environment through a variety of applications available that has a number of advantages.

Mid-range and high-end systems support
, Choices from the Red Hat Enterprise Linux AS 3 for the enterprise environment, the configuration of the kernel also only significant changes that can widen. Was shown at the time of the Linux kernel 2.6, 2.6 and compare not stand up in an enterprise environment, so that you can prepare for a real enterprise environment through Accept for the contents of memory, file system, and network, including a lot of support from 2.6. Of course, part of the 2.6 Multimedia On the other hand, except in an enterprise environment because it does not require 4GB-4GB of memory that are not supported in 2.6 for the split function or hyper-threaded CPU scheduler support functions were added.

Proven applications
Or unproven system that anxiety caused by a program consisting of migration from Unix or Windows. Red Hat 2.1 and Red Hat Redhat Ready Varsity unified in order to relieve this anxiety and maintain large software manufacturers and partnerships.

Status of Linux in the market

Linux market, parent company of small businesses and Bridge Expansion
From 109 IT professionals conducted by Zona Research survey, the majority of large enterprise respondents predicted that the number of Linux users within the enterprise to an additional 25% to 60% increase in the future, the overall response of 1.5, about 50% or more expected to increase.
Representatives of small businesses, more than 1/3 of the majority of the respondents had expected Linux using 50-80% increase Linux server e-mail / file / print services, the intranet server access, the standard Web server, Firefox Will and said that the purpose of 38% of the respondents revealed that using Linux database server, while 21 percent is used for e-commerce applications and

Linux adoption of a corporate CEO. Factors
Enthusiast in cold beliefs or emotions rather than MS opposition reliable, affordable bran, application performance, scalability, and openness is the result suggests that the most important factor in the adoption of Linux in the target survey CEO

3.Analysis
Spreading trend in the current Linux can be compressed down to three,
First ... Are the advantages of the major hardware vendors aggressive adoption of Linux (which has its own trends and Linux) Strong strategic aspects.
Second ... These advantages to the needs of enterprise customers have an advantage compared to other operating systems, etc., and is open source, reliability, stability, low cost, and short development cycle, and, above all, a step closer can get him.
And three ... The mainframes of the past or of today's computing environment, client / server environment, changes in the Internet environment was at the center of the network computing environment, these changes in the kernel changes
Important to the ability of Linux Customization Kills has created a competitive advantage.
There was the realization of this prospect is still in progress and the current rapidly. Current Red Hat Market
Castle rapidly growing trend and it fits for low server and has been released

Linux Vs Unix

Linux versa, but, Unix There are many different types of
Windows, such as Microsoft's Windows, but says Generally think that in many people's perceptions Unix, Solaris Unix, which among many Unix. Solaris because that led to it's Unix Technology Trend.

Unix NIS and NIS + are also like the concept of the Windows Domain Controller.
And Novell's NDS mimics the Windows Directory Service Active Directory Service as Unix (in this case, Sun Solaris), Sun ONE Directory Service. Other Unix does not have such a separate Directory Service. LDAP in conjunction with the course, you can

Thus Trend of technology that is occupied by the Sun Unix.
But the technology is superior, the most sold in the market is what is different. Novell combines Microsoft's O / S on the market than simply look to disprove this example are due to. Even if we can not be overlooked part of many marketing firm adherence to the No. 1 spot and the Sun's Unix Solaris 1 spot in the last year, on HP-UX must, and what might happen to watch the trend of the market which will

, Such as IBM's AIX, HP's HP-UX, Tru64 Unix, HP's former Compaq current SCO's Unix, Sun Solaris, the Unix, Unix is ​​the most similar. Not differ significantly is that Anyone who is familiar with Windows these reasons are not difficult to learn at first, the fact that Linux or Unix it was not for nothing that is true, but those who have studied the Linux or Unix is ​​not so difficult to study other vendors of Linux or Unix .

Anything any better is important, but a lot of market share to these two always equal to tens of thousands, to those who are studying, so will have to make choices, and production engineers need to learn what is required in their environment. Not easily encounter in the current market, by far the Sun Solaris high, then this is HP-UX. Is not just the fact that so many other Unix. Unix If you are studying in mind these parts seemed to be studying.

UNIX file system cleanup

UNIX file system
UNIX from DOS file system organization, and the ways it can be manipulated to have been strongly influenced. For this reason, the two operating systems are very similar. Files using the most work, read, copy, move, erase and take a look at this chapter you will see.
Larger files included in the directory, and the directories will be included in the directory, they are larger and can be included in the directory. djEJs specific file when you want to work with the system must be aware of the order to go to find the file in the directory. At this time is one way to specify the order and the name of the file to the pathname of the directory. Necessity, very similar, the biggest difference to use the DOS path separated by a backslash (\) UNIX that use slave sh (/), and the pathname of the UNIX and DOS.

* File operations
Anyone who is familiar with DOS and UNIX called DOS file extension (suffix) that will be noticed. This DOS and Unix important distinction is that most of the files in the DOS extension, but Unix generally is not. Unix, of course, also you can create a file name with an extension. For example, the text file is displayed as a file to create or kim.txt or yang.txt kim.pm or yang.pm cigars that can show However, because I believe most Unix users to enter as little as possible would be good if there is no reason not to use the extension, preferably avoiding the side.

* File read: more command
Success in the log when the following command: Get hit.
more kimdh
So ... will be shown on the screen kimdh in the DOS command and type comparable to the Unix more command both the contents of the file on the screen shows. In general, the command format is as follows.
more filename

* Note: the word "print"
For DOS users will be the meaning of the word "print" on a piece of paper act. In the Unix world, however, often the word "print" a document on the screen indicating the process means. For example, the contents of the file that says "print" more. Most Unix systems have the ability to print on paper output. However, Unix, can work productively without the need to print on paper in a way that will help people. Studying Unix, so please note the word "print", "show" that

shell from hitting more kimdh shows the contents of the file if this file is very large at the bottom of the screen will display the message shown on the screen, the first 24 lines of the ---- More ---. Need to read the rest of the contents of the first screen, you can choose from three methods.
1 press enter, the more shows the next line of the file. Continuously pressing Enter displays the file line-by-line basis.
By pressing the space key more of the file shows the following 24 lines. Space behind a screen showing the file will show a screen-by-screen basis.
More 3.q Pressing is finished. Find what you want from the file when you do not need to see anymore, so if you are more if you do not press q after the last line of the file until the display is finished.
If multiple files at once to investigate the following manner.
more kimdh yang
Do this first kimdh show yang of sequential file shows few files any more you can display the contents of a file at any time by using the n you can move on to the next file. In addition, if you would like to see behind the content of the file, go back and press p for the previous shows. Skip forward or backward within a file number for which, for example, may be used to go back as much as a three-screen, -3, +2, the two screens are skipped.

* Cat command
documents stopped because a screen-by-screen basis, the more command to read the file most convenient way. However, the cat command is slightly slower than the more command and the contents of multiple files Ehms one screen tight driveway without stopping just passed discarded.

* Ls ​​command
a short list of the files in alphabetical order according ls align
Note: the difference between ls and DIR
1.ls results are lowercase. DIR's, on the other hand, the result is almost capitalized.
2.ls results in alphabetical order, but it is sort DIR does not.
Provides detailed information, including the file's size and creation date, etc. 3.DIR. However, ls only displays only the name.

* Copy of the file - cp command
DOS users will be familiar with the copy command to copy the file. Unix command similar to the cp that. For example, a
# Cp kimdh yang
The kimdh the yang of the file will be copied to the And kimdh file missing remains. So cp without erasing the original files that only new files Makes know itjiyo.
Reference
Typically, when the DOS copy command to copy the file shows the message as 1File (s) copied. cp to copy the file, no message would have noticed. Is that a minimum level of output that keep the philosophy of Unix.

* Of deleted files - rm
Using the DOS DEL command to delete the file, remove abbreviation rm is used in Unix. For example, the
# Rm kimdh
You will get a message stating that the hydrothermal input file "kimdh" If so, the files will be erased. Kimdh the file is gone to make sure that "more kimdh" haebomyeon. This is because it has cleared the file that is Or, you can use the ls command to check is gone
Note: DOS DEL command and the differences between the Unix rm
DEL ignore everything except the first argument. For example,
# DEL kim kim1
Ten thousand kim do this does not erase erase kim1 Kim, kim1 "rm" command geureorh but is not clear.

* Move the file - mv command
Role of Unix mv command to move files. In DOS to think, is similar to the rename command. For example, a
# Mv kim kim1
Kim is doing so all will be moved to a file called kim1. However, "more kim" If you do not have a file will come out. Contrast this with the cp command, mv the new file, the original file is lost, Makes is. As a result, only the name of the file is changed.


**** **** Files and directories

Perhaps directory called DOS users will be familiar with the concept. DOS or UNIX directory'd concept is a way to organize the file contains. Quickly and easily find the files you want, wiha tying together over a similar type or purpose of the file is a directory.

* The root directory
/ U / jeon / hea / mylife
There is a directory name with a simple slash only of the things you can see above, this directory is called the root directory, all the Unix file system must have the root directory. To put it in more detail, the root directory of the file system can be described as a basic. All of the files in the file system must be included in one of the root directory or some subdirectory of the root.

* Pathname
Pathname is a way to specify the location of the file you want to work with. Is the full pathname to specify the pathname file system, such as wood and therefore Iran. In other words, until the end I place the file you want to start from the root note.
/ U / jeon / mylife
Above to view the full pathname can be here, there are a few components.
# The first element in the name of the start / This path must start from the root that means.
# The second element of the u. Are u looking for the fact that u is a directory in the root directory of the system you will find. Therefore, the path to the directory will be changed to u.
# The following elements jeon is to find u in the directory (/ jeon between u and only to distinguish between the elements.) System jeon Jeon directory that will know. So, again, jeon will go into the directory path.
# Last element is mylife. System mylife jeon find in the directory. Is the end of this path.
In other words, the path name or file until it reaches the desired directory into a hierarchy of consecutive directory, such as a map to guide.

* The current directory, specify the
"Pwd (print working directory)" If you want to know where his working directory as the current directory name shows. When you log in, the system automatically set the directory to the home directory called directory.

* Cd command
cd command will change the directory. kguswo And almost similar to the DOS CD command to write cd command without any arguments, then you will change the current directory to your home directory.

* Create a directory - mkdir command
mkdir command to create a new directory. As follows.
# Mkdir newdir
It under their current directory, create a directory named newdir.
Note: distinguish between files and directories
I thought maybe you'd have thought the file name and directory name looks a bit like a. File and directory names, and apparently it is because there is no difference. This is how to distinguish certain the name of the file or directory How do I know that you can use the ls-p. The ls-p option to display the directory name / character.

* Relative vs. absolute pathname pathname
Here's a general rule. If the pathname begins with a slash (/), the foot from the start it is the absolute pathname slash, if you start from the current directory pathname is relative to the start.

* Remove directory - rmdir command
rmdir command clears the directory.
# Rmdir newdir
This command eliminates the newdir directory.

* Common Directory
Most Unix systems have the following directory under the root directory.
# / Bin ---> in the system, this has a lot of utilities and programs viable. is an abbreviation of the bin is a binary file, binary utility is almost always a binary file.
# / Dev ---> device file, this has
# / Etc ----> used for any other purpose file system management, and has For example, / etc / passwd file has a name, typically all authorized users of their passwords and other kinds of personal information.
# / Tmp ---> save the temporary file to the user or program. For example, to align the contents of a file in Unix sort command, sometimes temporarily storing the partial alignment of the contents of the file disk space is required. If so, when you sort the / tmp partially finished working to create a file under / tmp from the temporary file clears.
# / U ----> form of user directory system has Files and directories that can be stored under the directory for technical reasons, there is no limit to the number of Therefore, with those used by many Unix systems form in the directory / u do not all fit in the other directories may be required. Riga Is seen overflowing for users home directory that stores such as / usr, / u1, / u2 of the directory name.


Characteristics of the file **** ****

* File Permissions File Permissions
Unix files are three kinds of permissions is as follows.
The owner of the file
On Unix systems, all users assigned a unique user id number, called number received does. Will be licensed to use the system it is assigned automatically when Belongs to the owner of the owner of the file permissions. For example, if you are the only one who can not read or write any file because you can set the permissions of the files that are owned.
Unix group of users
Unix system administrator can create a group on the system. For example, a system administrator to use the computer for each project, or create a group separate from the company each department to create a group. System administrator, you can go in either group Which group is the primary group is determined.
3 other licensed
Did not own the file or the file permissions to all people who do not belong to the group. For example, to use the system, so that everyone can read, you can set up a file.

File permissions *
There are three types of file permissions.
r> to read the file permissions
w -> write permission on the file
x -> paeul the permission to run, for example, any executable program file, then x permission to run the program you need.
The kind permission of the file owner, group, and can be assigned to all users by separating. They always rwx's in the order listed. For example, a
rw-r - r-w
Above, the first three letters of the owner's permission rw-means to write, to think, but can not run. The following three letters means the group permissions. r - read permission, write, and execute permissions, but not the meaning. The last three letters of the other rights. r - read books one and execute permissions, but not write permission means.

Permissions on the directory *
r ---> permission to read any directory on the file that contains the directory and western, only just be able to read only the name. Diary of the file itself will need permission to read the contents of the file.
w -----> any directory permission to create new files and subdirectories under the
This is weaker than r x -----> Navigate to the directory where the rights, privileges. Particular file or sub-directory to determine if there are. when r you do not have permission to know the names of the x permission, which, if you can access the file or subdirectory. , However, not be able to traverse the directory in order to find out the names contained in the directory.

* File attributes --- ls-l
the format of the ls command to show the attributes of the file or directory. Try the following:
ls-l jeon
Dash (-l lowercase l.) The output of this command is as follows.
-Rwxrwxrwx 1 suo93 0 707 Feb 17 10:00 jeon
Your computer and coming up in this way, however, will not be exactly the same. Well, one of the results we'll briefly look up the meaning.
Dash ---> the first character of the file is a directory, d will
means rwxrwxrwx ---> to the file permissions for owner, group, and all users have full access to files that shows
1 ------> Link to file number.
suo93 ---> The user ID of the file's owner. This is a Unix / information imported from the file and stored in the etc directory. And the file name for the first time in less regarded as the person who owns all the files on your computer.
0 ----> group of files. This also Unix because DOS is taken from the files and information stored in the / etc group always has a value of 0.
707 ---> the size of the file. Still be displayed in bytes.
Feb 17 10:00 ---> This is the date and time the file was last changed. Directory, the directory is created, the date and time.
jeon ---> is the name of the file or directory.

* Chmod command
chmod command to set permissions for the file or directory. general format of this command is as follows:
chmod perms name
perms point to the desired permission must be set to the name of the authority is the name of the file or directory. perms argument can have many forms, but are mainly used as follows:
To set permissions for who want to use one or more letters. Owns man u, group g, o, for everything a use.
+, Otherwise that would like to give permission for use.
That represent the permissions you want to use or do not want, you must use one or more letters. Need to use the letters r, w, x.
Example As an
chmod a-rwx file
chmod u + rwx file
chmod g+ r file
The first command, then the owner's permission to abems and limit the rights of all users of all allowed in the final group for the diary privileges allowed. A result giti users are not able to do anything to the file, the group has only read-only, and the owner will have the right to do everything.

* Null device (Null Device)
Under many Unix systems, / dev / dev / null is a special file called. Very common in a Unix file. Any data whatever wrote to / dev / null, it will be lost for ever. So why this feature needs is wondering is. It is also what users want to ignore the results of the program is that / Dev / ull simply the result in such cases is simply send Will receive them immediately as soon as the file has reached the end of the message when trying to read something from / dev / null. / Dev / null, so you empty file or a file called. Outgoing data is never coming here is that there is no law.