NT's file systems allocate the disk sectors of logical drives (e.g., C, D) in units known as clusters. When you create a file on a drive, the file system assigns clusters of storage for the file's data. As time passes and you expand and shrink the file and create and delete other files, both the free clusters on the drive and the clusters assigned to the files become fragmented (i.e., non-contiguous)

The defragmentation support introduced in NT 4.0's file systems consists of five commands: GetVolumeBitmap, GetRetrievalPointers, and MoveFile (common to both FAT and NTFS), and GetVolumeData and ReadMFTRecord (specific to only NTFS)

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The modem, printer, or other peripheral equipment is identified as the Data Communications Equipment (DCE). The DCE is sometimes referred to as the device.

A way to create software programs in small modules that are called objects. They are reusable and can talk among each other. It is a way to get away from monster size software applications that are really difficult to maintain, and at the same time be able to run these modules (objects) on different computers so you can distribute the CPU load.

   About how to set up and use the Display Heap tool (Dh.exe, a NT resource kit tool ) to troubleshoot User-mode memory leaks in processes and services.

   Dh.exe is a character-mode tool for displaying information about heap allocations in a process, or pool usage in Kernel-mode memory.

   When the heap-tracking global flags are set in the registry (GlobalFlag at Session Manager) , a database is created at system startup that contains real-time information about memory allocation activities. At the instant that an allocation or a free is performed, a snapshot of the current thread's stack is recorded and stored in the database. You can use this information to identify the cause of a memory leak.
 
   The debug symbols must be installed in the %SystemRoot%\Symbols folder.

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   Short for Dynamic Host Configuration Protocol, a protocol for assigning dynamic IP addresses to devices on a network. With dynamic addressing, a device can have a different IP address every time it connects to the network. In some systems, the device's IP address can even change while it is still connected. DHCP also supports a mix of static and dynamic IP addresses.

    Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather than requiring an administrator to manage the task. Many ISPs use dynamic IP addressing for dial-up users.

    DHCP's purpose is to enable individual computers on an IP network to extract their configurations from a server (the 'DHCP server') or servers, in particular, servers that have no exact information about the individual computers until they request the information. The overall purpose of this is to reduce the work necessary to administer a large IP network. The most significant piece of information distributed in this manner is the IP address.

Obtaining Configuration Parameters Using DHCP

    When a DHCP-enabled client boots for the very first time, it broadcasts a DHCP Discover request onto the local subnet. Any DHCP server that receives the request may respond with a DHCP Offer that contains proposed configuration parameters. The client can evaluate the offer, and respond with a DHCP Accept Request to accept it. The server finalizes the transaction with a DHCP Acknowledgment.

Lease Expiration and Renewal

    DHCP-supplied configurations are "leased" from the server. Periodically, the client will contact the server to renew the lease. The protocol and implementation are very robust and configurable and short-term server or network outages do not generally affect lease renewal. For instance, DHCP clients start to try to renew their lease when 50% of the lease time has expired. Repeated attempts are made to contact the DHCP server and renew the lease, until 87.5% of the lease time has expired. At this point, the client attempts to get a new lease from any available DHCP server.
When a DHCP client is rebooted, it attempts to verify that the lease it holds is valid for the current subnet. If it is moved to another subnet and rebooted, the following sequence takes place:
 

Source MAC  Dest MAC     Source IP   Dest IP          Pro     Description
davemacp    *BROADCAST   0.0.0.0     255.255.255.255  DHCP    Request  (xid=6E3A2E74)
router      *BROADCAST   10.57.8.1   255.255.255.255  DHCP    NACK     (xid=6E3A2E74)
davemacp    *BROADCAST   0.0.0.0     255.255.255.255  DHCP    Discover (xid=51CA7FED)
router      davemacp     10.57.8.1   10.57.13.152     DHCP    Offer    (xid=51CA7FED)
davemacp    *BROADCAST   0.0.0.0     255.255.255.255  DHCP    Request  (xid=2081237D)
router      davemacp     10.57.8.1   10.57.13.152     DHCP    ACK      (xid=2081237D)

    An Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they're easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.microsoft.com would be translated to 198.105.232.4. You can see that they're the same by substituting the number for the name in the URL http://www.microsoft.com and entering it in a Web browser.
The DNS system is, in fact, its own network. If one DNS server doesn't know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned.

Integration of the DNS and WINS

    The DNS can be configured with a special "$WINS" directive, that instructs it to pass through to a WINS server queries for names that can't be found in the DNS database. The algorithm for passing through queries is:
 

• Attempt to resolve the name to an IP address using standard DNS records.
• If that fails, the domain suffix is stripped off, and a NetBIOS name is formed by space padding the hostname and appending 0x00 as the 16th character. The WINS server configured for the host running the DNS software is then sent a standard NetBIOS name query for that name.
• The WINS server returns a Name Query Response, and if it was successful the DNS returns a standard DNS response to the original client using the information obtained from WINS.

• Host "A" sends a DNS query for beetle.microsoft.com to the DNS.
• The DNS checks its records and finds no match.
• The DNS sends a NetBIOS Name Query to its WINS server for "BEETLE<00>" (BEETLE followed by 9 spaces and hex 00).
• The WINS server locates the (dynamically registered) IP address for BEETLE and returns it to the DNS in a NetBIOS Name Query Response.
• The DNS returns the resource record to Host "A" as a DNS response.

Referencias

A DOMAIN consists of a group of computers that have a common security database and recognize the same user accounts. All of the security information for the domain is stored on one computer in the domain called the Domain Controller. The computers in a domain can be administered as a group. Members of a certain domain can log on to any computer in that domain. Only those users designated by the system administrator can be a member of a domain. However, anyone can be a member of any workgroup.

Drivers make device independence possible for Windows NT applications, providing the hardware specific interface between physical devices and Windows NT. The Setup program can install several kinds of drivers for Windows NT.

 Data Terminal Equipment (DTE). The DTE is sometimes called the host: it is the computer in a computer-printer environment.