What is..........???

What is Global Catalog Server?

A global catalog server is a domain controller it is a master searchable database that contains information about every object in every domain in a forest. The global catalog contains a complete replica of all objects in Active Directory for its host domain, and contains a partial replica of all objects in Active Directory for every other domain in the forest. It have two important functions:

·                                 Provides group membership information during logon and authentication

·                                 Helps users locate resources in Active Directory

What is IPv6?

Internet Protocol version 6 (IPv6) is a network layer IP standard used by electronic devices to exchange data across a packet-switched internetwork. It follows IPv4 as the second version of the Internet Protocol to be formally adopted for general use.  ip v6 it is a 128 bit size address. This is total 8 octants each octant size is 16 bits separated with “:”, it is in hexa decimal format. These 3 types:

1.             unicast address

2.             multicast address

3.             anycast address

loopback address of ip v6 is ::1

What is Active Directory schema?

The Active Directory schema contains formal definitions of every object class that can be created in an Active Directory forest it also contains formal definitions of every attribute that can exist in an Active Directory object.

Active Directory stores and retrieves information from a wide variety of applications and services.

Describe the lease process of the DHCP server.

DHCP Server leases the IP addresses to the clients as follows: 

DORA
D (Discover) : DHCP Client sends a broadcast packets to identify the dhcp server, this packet will contain the source MAC.
O (Offer) : Once the packet is received by the DHCP server, the server will send the packet containing Source IP and Source MAC.
R (Request) : Client will now contact the DHCP server directly and request for the IP address.
A (Acknowledge) : DHCP server will send an ack packet which contains the IP address.

What is the ntds.tit file default size?

 Ans: 40 MB 

What is.....???

1. What is NIC? 

A network card, network adapter or NIC (network interface controller) is a piece of computer hardware designed to allow computers to communicate over a computer network

2. What is USB?

Universal Serial Bus (USB) is a serial bus standard to interface devices. Devices like Modem, Mouse, Keyboard etc can be connected.

3. Dialup vs. Broadband

A broadband connection (ADSL) provides high-speed Internet access over a standard phone line. The advantage of a broadband connection over a standard dialup service, is that Broadband is considerably faster, and is "always-on", meaning that once you"re logged on, your PC is online until the PC is turned off again.

Broadband offer high-speed Internet access and allows telephone calls and a permanent Internet connection to share a single phone line simultaneously whereas in Dialup connection either Internet connection or telephone call can made at given time.

4. LAN and WAN

A local area network is a computer network covering a small geographic area, like a home, office, or group of buildings

Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries). Or, less formally, a network that uses routers and public communications links

5. Microsoft Access

Microsoft Office Access, previously known as Microsoft Access, is a relational database management system from Microsoft.

6. What is RAS?

Remote Access Services (RAS) refers to any combination of hardware and software to enable the remote access to tools or information that typically reside on a network of IT devices.

7. Difference between Client Mail and Web Mail?

Email clients download your emails onto your computer. Using a specialized email program such as Outlook Express or Apple Mail has the advantage of giving you complete control over your email; every email you receive is placed on your computer and you can keep as many large file attachments as you want.
Checking your email through our webmail is similar to using Hotmail or Yahoo! Mail. You never actually copy your messages to your computer; in fact, you are looking at them through your web browser on somebody else"s computer. When you are not online, you are not able to see your email.

8. RAM and ROM

random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.

Pronounced rahm, acronym for read-only memory, computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read. Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.

9. Spamguard

Spam Guard is an Outlook add-in that filters email that arrives in your inbox. If the sender of any message cannot be identified then the message is moved into a spam quarantine folder. Messages deposited in the spam quarantine folder can be inspected and either deleted or approved at your leisure.

10. Firewall and Antivirus 

A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
Antivirus is a software program which helps protect a computer against being infected by a virus.

11. DNS

Short for Domain Name System (or Service or Server), 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.example.com might translate to 198.105.232.4.

12. IPConfig

IPConfig is a command line tool used to control the network connections on Windows NT/2000/XP machines. There are three main commands: "all", "release", and "renew". IPConfig displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings. Used without parameters, IPConfig displays the IP address, subnet mask, and default gateway for all adapters.

13. Trace route

Trace route is the program that shows you the route over the network between two systems, listing all the intermediate routers a connection must pass through to get to its destination. It can help you determine why your connections to a given server might be poor, and can often help you figure out where exactly the problem is. It also shows you how systems are connected to each other, letting you see how your ISP connects to the Internet as well as how the target system is connected.

The Definition of a Network Router for the Non-technical Person

Router is a term that a lot of us hear but few people outside of computer science have a true understanding of. Sure, it is that box that we plug into our modem that gives us wireless Internet. Of course, that definition is simplistic at best and kind of like saying that a car can be summed up as a box on four wheels. If you want a more basic understanding of what a network router is, then this piece can help you. We’ll take a look at a more detailed definition of a router and a look at some of the common types you might encounter, as well as some that few will ever see but that are still worth knowing about.

A More Detailed Definition of a Router
A router is a networking device that has specific software and hardware which has been designed for the routing and forwarding of information. What this means is that routers are specialized devices for transmitting data. As a general rule, routers operate on two different planes: the control plane and the forwarding plane, both of which deal with interfaces and outbound data. A router's primary job is to provide connectivity, a function which you may be most familiar with in your own home from your wireless network setup. Routers, of course, are also used by larger systems including your original Internet service provider.

The Types of Routers
For the most part, there are four basic types of routers that you may encounter on a computer network.
The Edge Router
The edge router is, as you may have guessed, one that sits on the edge of an ISP's network. It is the edge router's job to route data externally to either another service provider or a large enterprise's autonomous system. These are most common in the world of business.
Subscriber Edge Router
The subscriber edge router is similar in function to standard edge router except in its function on the edge of the subscriber’s network and that it is used to transmit data into the subscribers network.
Inter-Provider Border Router
Figure provider border routers are used to interconnect ISPs. These routers maintain what is known as the BPG which allows two routers, such as an edge router and the subscriber edge router, to talk to each other and transmit data.
Core Router
A core router is used inside an ISP and transmits internally. They may be used to connect as your border routers or simply to pass signals within the network. While traditionally the core has been in the backbone of the system, as the design of modern networks changes, finding the core can be more and more challenging. Generally where the drivers are now is consider the core.

Router Size
It is important to know that there are two main sizes of routers. The first are small office and home office (SOHO) connectivity routers. These are the routers that most people are familiar with. They allow you to connect to your cable or DSL on a small scale. Enterprise routers, on the other hand, are usually confined to large companies and universities as well as research facilities and ISPs. While these allow for basically the same function, they are infinitely more powerful.