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Windows Server 2003 Active Directory and Network Infrastructure

It is a hierarchical representation of all the objects and their attributes available on the network. It enables administrators to manage the network resources, i.e., computers, users, printers, shared folders, etc., in an easy way. The logical structure represented by Active Directory consists of forests, trees, domains, organizational units, and individual objects. This structure is completely independent from the physical structure of the network, and allows administrators to manage domains according to the organizational needs without bothering about the physical network structure.

Following is the description of all logical components of the Active Directory structure:

Forest: A forest is the outermost boundary of an Active Directory structure. It is a group of multiple domain trees that share a common schema but do not form a contiguous namespace. It is created when the first Active Directory-based computer is installed on a network. There is at least one forest on a network. The first domain in a forest is called a root domain. It controls the schema and domain naming for the entire forest. It can be separately removed from the forest. Administrators can create multiple forests and then create trust relationships between specific domains in those forests, depending upon the organizational needs.

Trees: A hierarchical structure of multiple domains organized in the Active Directory forest is referred to as a tree. It consists of a root domain and several child domains. The first domain created in a tree becomes the root domain. Any domain added to the root domain becomes its child, and the root domain becomes its parent. The parent-child hierarchy continues until the terminal node is reached. All domains in a tree share a common schema, which is defined at the forest level. Depending upon the organizational needs, multiple domain trees can be included in a forest.

Domains: A domain is the basic organizational structure of a Windows Server 2003 networking model. It logically organizes the resources on a network and defines a security boundary in Active Directory. The directory may contain more than one domain, and each domain follows its own security policy and trust relationships with other domains. Almost all the organizations having a large network use domain type of networking model to enhance network security and enable administrators to efficiently manage the entire network.

Objects: Active Directory stores all network resources in the form of objects in a hierarchical structure of containers and subcontainers, thereby making them easily accessible and manageable. Each object class consists of several attributes. Whenever a new object is created for a particular class, it automatically inherits all attributes from its member class. Although the Windows Server 2003 Active Directory defines its default set of objects, administrators can modify it according to the organizational needs.

Organizational Unit (OU): It is the least abstract component of the Windows Server 2003 Active Directory. It works as a container into which resources of a domain can be placed. Its logical structure is similar to an organization`s functional structure. It allows creating administrative boundaries in a domain by delegating separate administrative tasks to the administrators on the domain. Administrators can create multiple Organizational Units in the network. They can also create nesting of OUs, which means that other OUs can be created within an OU.
In a large complex network, the Active Directory service provides a single point of management for the administrators by placing all the network resources at a single place. It allows administrators to effectively delegate administrative tasks as well as facilitate fast searching of network resources. It is easily scalable, i.e., administrators can add a large number of resources to it without having additional administrative burden. It is accomplished by partitioning the directory database, distributing it across other domains, and establishing trust relationships, thereby providing users with benefits of decentralization, and at the same time, maintaining the centralized administration.

The physical network infrastructure of Active Directory is far too simple as compared to its logical structure. The physical components are domain controllers and sites.

Domain Controller: A Windows 2003 server on which Active Directory services are installed and run is called a domain controller. A domain controller locally resolves queries for information about objects in its domain. A domain can have multiple domain controllers. Each domain controller in a domain follows the multimaster model by having a complete replica of the domain`s directory partition. In this model, every domain controller holds a master copy of its directory partition. Administrators can use any of the domain controllers to modify the Active Directory database. The changes performed by the administrators are automatically replicated to other domain controllers in the domain.

However, there are some operations that do not follow the multimaster model. Active Directory handles these operations and assigns them to a single domain controller to be accomplished. Such a domain controller is referred to as operations master. The operations master performs several roles, which can be forest-wide as well as domain-wide.

Forest-wide roles: There are two types of forest-wide roles:

Schema Master and Domain Naming Master. The Schema Master is responsible for maintaining the schema and distributing it to the entire forest. The Domain Naming Master is responsible for maintaining the integrity of the forest by recording additions of domains to and deletions of domains from the forest. When new domains are to be added to a forest, the Domain Naming Master role is queried. In the absence of this role, new domains cannot be added.

Domain-wide roles: There are three types of domain-wide roles: RID Master, PDC Emulator, and Infrastructure Master.

RID Master: The RID Master is one of the operations master roles that exist in each domain in a forest. It controls the sequence number for the domain controllers within a domain. It provides a unique sequence of RIDs to each domain controller in a domain. When a domain controller creates a new object, the object is assigned a unique security ID consisting of a combination of a domain SID and a RID. The domain SID is a constant ID, whereas the RID is assigned to each object by the domain controller. The domain controller receives the RIDs from the RID Master. When the domain controller has used all the RIDs provided by the RID Master, it requests the RID Master to issue more RIDs for creating additional objects within the domain. When a domain controller exhausts its pool of RIDs, and the RID Master is unavailable, any new object in the domain cannot be created.

PDC Emulator: The PDC emulator is one of the five operations master roles in Active Directory. It is used in a domain containing non-Active Directory computers. It processes the password changes from both users and computers, replicates those updates to backup domain controllers, and runs the Domain Master browser. When a domain user requests a domain controller for authentication, and the domain controller is unable to authenticate the user due to bad password, the request is forwarded to the PDC emulator. The PDC emulator then verifies the password, and if it finds the updated entry for the requested password, it authenticates the request.

Infrastructure Master: The Infrastructure Master role is one of the Operations Master roles in Active Directory. It functions at the domain level and exists in each domain in the forest. It maintains all inter-domain object references by updating references from the objects in its domain to the objects in other domains. It performs a very important role in a multiple domain environment. It compares its data with that of a Global Catalog, which always has up-to-date information about the objects of all domains. When the Infrastructure Master finds data that is obsolete, it requests the global catalog for its updated version. If the updated data is available in the global catalog, the Infrastructure Master extracts and replicates the updated data to all the other domain controllers in the domain.

Domain controllers can also be assigned the role of a Global Catalog server. A Global Catalog is a special Active Directory database that stores a full replica of the directory for its host domain and the partial replica of the directories of other domains in a forest. It is created by default on the initial domain controller in the forest. It performs the following primary functions regarding logon capabilities and queries within Active Directory:

It enables network logon by providing universal group membership information to a domain controller when a logon request is initiated.

It enables finding directory information about all the domains in an Active Directory forest.

A Global Catalog is required to log on to a network within a multidomain environment. By providing universal group membership information, it greatly improves the response time for queries. In its absence, a user will be allowed to log on only to his local domain if his user account is external to the local domain.

Site: A site is a group of domain controllers that exist on different IP subnets and are connected via a fast and reliable network connection. A network may contain multiple sites connected by a WAN link. Sites are used to control replication traffic, which may occur within a site or between sites. Replication within a site is referred to as intrasite replication, and that between sites is referred to as intersite replication. Since all domain controllers within a site are generally connected by a fast LAN connection, the intrasite replication is always in uncompressed form. Any changes made in the domain are quickly replicated to the other domain controllers. Since sites are connected to each other via a WAN connection, the intersite replication always occurs in compressed form. Therefore, it is slower than the intrasite replication.

1IT-Network communication
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What is Hyperterminal?

Hyperterminal is a program that is designed to perform the functions of communication and terminal emulation. Also known as HyperTerm, the program has been offered as part of Microsoft operating systems since the release of Windows 98. Essentially, Hyperterminal can make it possible to make use of the resources of another computer by establishing a link between the two systems.

What Can Hyperterminal Do?

The original design for Hyperterminal made it possible to use a standard telephone line to establish a dialup connection between two computers. The program would make use of the internal modem of the host or main computer and use a service such as Telnet to establish the connection to the secondary computer. This connection could be exploited to transfer data and files from one system to the other, without the need to save data to some sort of exterior device and then manually load the data onto the other system.

Along with making data transfer between two computers a relatively easy process, Hyperterminal also made it possible for the main system to access and utilize a bulletin board service located on the second system. The program can also be used to troubleshoot issues with modems, or help to make sure a newly installed modem is functioning correctly.

How Does Hyperterminal Work?

Hyperterminal makes use of serial ports and the controls associated with external devices. These devices can vary and include such options as radio communications equipment, robots, and instruments used for scientific measurements and similar endeavors. The connections provided by Hyperterminal make it easy to retrieve data from these sources, as well as be able to execute commands to the devices from the main computer system.

When checking the status and operability of a device such as an exterior modem, Hyperterminal can be used to verify that the connections are aligned properly and that the command to activate the dialer on the modem is functioning properly. Essentially, Hyperterminal sends a mock command to the modem and walks the device through all the steps of establishing connectivity with the network. Accessing Hyperterminal is easily accomplished through the Start menu of any Windows based system.

1IT-Network datarec
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Microsoft Word repair tool

Recovery Toolbox for Word is a program for Word file repair, it helps to repair docx files, if it was not possible to prevent data corruption. Many users regularly see error messages, when opening *.doc files. Stay calm, when Word unable to read file, we will be glad to suggest a solution. Recovery Toolbox, Inc. suggest trying Word file repair tools, that can be found on our website, just click on "Download" and save the installation file of Recovery Toolbox for Word to your hard disk.

Recovery Toolbox for Word features easy system requirements, this program will work on all PC`s and with all supported versions of Microsoft Windows and Microsoft Word. Word repair tools are easy to use, we believe, that instructions will not be needed in your case. However, we are always ready to respond all request within a reasonable time. Feel free to forward us your opinion with regard to Microsoft Word repair tool and other programs to repair docx file.

All users can preview the data, when repair Word file and make sure, that the money will not be paid for nothing. The service of repair docx works, it requires minimal user intervention, so, the process of data recovery can be done even for beginners. You have a great chance to test this data recovery service for free, demo version is distributed without restrictions. Just do not forget to let us know your opinion about Recovery Toolbox for Word, we need it to improve existing services. Please register your copy of Recovery Toolbox for Word to remove all restrictions.

Product page: http://www.recoverytoolbox.com/repair_word.html

Screenshot: http://www.recoverytoolbox.com/img/screenshot_rt_word_01big.gif

Download Link: http://www.recoverytoolbox.com/download/RecoveryToolboxForWordInstall.exe

Buy page: http://www.recoverytoolbox.com/buy_word.html

1IT-Network compcert
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Enhance your computer knowledge with latest technology at ABCO

There are several types of computer training course available to the person seeking to learn about computers today. Generally the term computer training comprises everything related to the computer as a whole. This training consists of lessons on the various parts of the computer, their functions and necessities and then the manner to compute or run the computer. Also the content of this kind of computer trainings are based on the term or duration of the training procedure.

To start, it would be a good course of action to look at classes teaching the basics of how to operate a computer. It is a good idea in the computer training course to also learn some basics about the internal operation of the computer (i.e., what makes it tick, how it works). Student self-respect is also important. A good trainer must develop the feeling that it`s okay to be wrong and that being wrong does not imply that a student is ignorant. The importance of computer is nowadays felt in each and every sphere. Right from the beginners of the primary schools to the big industrialists, everyone comes in touch with the computers. This immense importance of the computers has led to the necessity of computer training to a great extent. Therefore it will be worthwhile to know about the several types of computer training and its impact and usefulness in our life.

Moving on from the basics, a computer training course should teach more advanced concepts as well. Some of these concepts would include back-up procedures, file maintenance, and data recovery. In the short term computer training classes, the emphasis is put on making the student aware of the general and basic computer term and a basic learning is provided with which the primary computer functions can be done. We prepare students by delivering hands-on job oriented training which teaches them how to apply the knowledge that they gain in classes along with preparing them to pass the vendor based certification exams. We have partnered with Microsoft, Oracle, Linux , Cisco Systems, Prometric testing center and as such offer wide variety of computer training that include but are not limited to Microsoft Certification, A+ training, CISCO Certification Course, Oracle Certification Course, Internet and Microsoft Office 2003.

The importance of the computer training is rapidly increasing as it is required in each and every field in this fast growing world. Even the housewives too need to know the basics of the computer if they want to be an efficient home manager. Shopping, cooking, cleaning everything has become computerized nowadays. Even for guiding the little one in their school homework, the mother should have the primary computer knowledge. Keeping in mind this vital role of the computers numerous computer training institutions have opened up where any class and any age group can get admitted and take lessons. Also, the online computer training courses have made this procedure far more easy and accessible for the learners. Those who are very busy and find it tough to manage time for rushing to the institutes have been helped to a great extent by this online computer learning system.

ABCO Technology specializes in providing Computer Training and Consulting for the Information Technology Industry. Computer Training is provided by experienced, certified industry experts that have years of seasoning in their respective field of Information Technology.

If you would like to do computer training courses at ABCO Technology, then kindly free to visit our website:- http://www.abcotechnology.com/

1IT-Network wireless-network
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Router - Denial Of Service Attacks

Routers are not perfect. For that matter, nothing is. So if somebody wants to give a router more than it can handle there is a way to do this. We`re going to take a look at what are called denial of service attacks.

A router can only handle so much information coming into it at one time. Every machine has its limits and routers are no exceptions. Well, when the nasty trend of denial of service attacks started early this century, routers were unprepared for them. As they began to understand what was happening they began to compensate for the problem. But there was still a way around it. To understand this we first have to understand what a denial of service attack is.

A denial of service attack is just as it sounds. It is when someone prevents the router or routers from servicing the network. The question is, how do they do this? As previously stated, a router can only handle so much information coming into it to be routed at a time. If too much information starts coming in then the router gets overloaded and can`t forward the information fast enough. Ultimately, what happens is this slows the network down to the point where nobody can access it. In a denial of service attack, which is a deliberate attempt to cause this problem, a person will send an enormous amount of information from one computer to the router at one time. Eventually this will effectively shut down the network. The reason is because of the trickle down effect. Once the main routers start to get overloaded they start to send messages to the rest of the network that the connection is full. These messages start to cascade through the entire network until all the pathways in the network are full and nobody can communicate with any server on the network.

When companies and web sites began to understand what was happening then started to put safeguards in place. They would put checks in the router software to see if a large amount of information was coming from one IP address. If so, then it simply discarded the information and didn`t attempt to pass it on. It seemed that the problem was solved. Not so.

Hackers began to figure out that if they send this enormous amount of information from multiple computers or IP addresses, the routers would have no way of knowing that a denial of service attack was in progress because it would see all this information coming in from multiple locations. Ultimately again, the network would effectively be shut down.

In response to this, manufacturers of routers have placed additional safeguards into their routers to simply check for unusual traffic. The problem with this is that in some cases there is a large amount of traffic that is normal, like in the case of a news site being hit with an overload because a major breaking story hits the airwaves.

It remains to be seen if the hackers or the router manufacturers are going to win this war.

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