UDP: (USER DATAGRAM PROTOCOL) ::

User Datagram Protocol (UDP) User Datagram Protocol (UDP) is a connection less transport layer protocol (Layer 4) that are on the internet protocol family.

 UDP is basically an interface between IP and upper layer processes. UDP protocol ports distinguish multiple applications running on a device from each other. Unlike TCP, UDP adds no reliability, flow control, or error-recovery functions to IP. Because UDP's simplicity, UDP headers contain fewer bytes and consume less network overhead than TCP.

 UDP is useful in situations where the reliability mechanisms of TCP are not necessary, as when a higher layer protocol can error and flow control condition. UDP is the transport protocol for several well-known-application protocol layers, including Network File System (NFS), Simple Network Management Protocol (SNMP), Domain Name System (DNS) and Trivial File Transfer Protocol (TFTP).

UDP packet format contains four fields, This includes areas of source and destination ports, length and checksum.

TCP (TRANSMISSION CONTROL PROTOCOL) ::

TCP provides reliable transmission of data in an IP environment. Corresponding TCP transport layer (layer 4) of the OSI reference model. Among the services TCP provides are stream data transfer, reliability, efficient flow control, dual full cooperation and multiplexing. With stream data transfer, TCP delivers an unstructured stream of bytes identified by serial numbers.

This service benefits applications because they have no data to cover the blocks before handing it to TCP. Instead, TCP groups bytes into segments and passes them to IP for delivery. TCP offers reliability by providing connection-oriented, providing end-to-end reliable packet through an Internetwork.

 It does this by sequencing bytes sent acquaintance with a number indicating the next byte source destination expects to receive. Bytes not acknowledged within a certain period is retransmitted. Reliability mechanism of TCP allows devices to deal with lost, delayed, duplicate or incorrect packages.

A timeout mechanism allows the equipment lost packets and retransmission request to discover. TCP offers efficient flow control, which means that when sending acknowledgments back to the source, receiving TCP process indicates the highest sequence number can receive without overflowing its internal buffers.

 full duplex operation means that TCP processes can both send and receive at the same time. Finally, TCP multiplexing means that the multiple simultaneous high-level talks may be multiplexed over a single connection.

ICMP PACKET::

ICMPs generate different kinds of useful messages, including destination unreachable, Echo Request and Response Redirect, Time exceeded, and Router Advertisement and Router Soloists. If an ICMP message can not be saved, there is a second is created. It is an endless stream of ICMP messages are avoided.

When a message ICMP destination-unreachable is sent by a router, this means that the router is not able to send packets to the final destination. Router then throw the original package. There are two reasons why an unreachable destination will be. More broadly, the host resource specified a nonexistent address. Less commonly, the router does not have a route to the destination.

 Destination-unreachable messages consists of four basic types: network unreachable, host unreachable, protocol unreachable, and port unreachable. Network-unreachable messages usually mean that a failure has occurred in the course or treatment of a package.

 Host-unreachable messages usually indicate liver failure, such as incorrect subnet mask. Protocol-unreachable messages generally mean that the destination does not support upper layer protocol packets.

Port-unreachable messages means that the TCP socket or port is not available. An ICMP echo request message, which was created ping command is sent from a host is required to achieve test on a job site. ICMP echo-reply message indicates that the node can be achieved successfully. ICMP Redirect message is sent from router to source host to stimulate more efficient routing.

 The router still forwards the original packet to the destination. ICMP redirects allow host routing tables remain small, it is necessary to address only a router to know, even if the router is not the best way. Even after an ICMP Redirect message, some devices can continue with the road less efficient...

ARP (ADDRESS RESOLUTION PROTOCOL) ::

Address Resolution Protocol (ARP)::

 Summary For two machines in a data network to communicate, they know another physical machine (orMAC) addresses. By broadcasting Address Resolution Protocols (ARP), a host can dynamically discover the MAC layer address corresponding to a network layer address IP.

 Upon receipt of AMAC-layer address, IP devices create an ARP amount of recently acquired IP-to-MAC address mapping store, and in this way Arps broadcast when they want a device to recontact. If the device within a specified time, the cache entry flushed.

 In addition to Reverse Address Resolution Protocol (RARP) is used for layers mapMAC addresses IP addresses. RARP, which is the logical inverse of ARP, can be used by diskless workstations that are not their IP addresses to know when their boat.

 RARP relies on the presence of a RARP server with an entry MAC address table mappings-layer-to-IP.

IP SUBNET:

IP Subnet address ::

IP networks can be divided into smaller networks called subnetworks (or subnets). Subnet provides the network administrator with several benefits, including extra flexibility, more efficient use of network addresses, and the ability to broadcast traffic (a broadcast will not cross a router) have.
 Subnets are under local administration.

As such, the outside world sees an organization as a single network and have no detailed knowledge of the organization's internal structure. A given network address can be broken up into many subnetworks.

For example, 172.16.1.0, 172.16.2.0, 172.16.3.0 and 172.16.4.0 are all subnets within network 171.16.0.0. (All 0s in host portion of an address specify the network.)

IP PACKET FORMAT::

The following discussion describes the IP packet.

• Version indicates the version of IP currently used.

• IP Header Length (IHL)-Indicates the datagram header length in 32-bit words.

 • Type-of-Service-Specifies how an upper layer protocol would be a current datagram to deal and knows datagrams various levels of interest.

• Total Length Specifies the length, in bytes, of the entire IP packet, including the dates and headline.

 • Identification-Contains a number that identifies the current datagram. This field is used to help piece together datagram fragments.

• Flags-Consists of a 3-bit field of the two low-order (at least-significant) bits control fragmentation. The low-order bit determines whether the packet can be fragmented. The middle bit determines whether the packet is the last fragment in a series of fragmented packets. The third or high-order bit is not used.

 • Fragment Offset indicates the position of the fragment's data in relation to the start of the data in the original datagram, which allows the destination IP process to properly reconstruct the original datagram.

• Time-to-Live-Maintains a counter that gradually decrements down to zero, at which point the datagram is discarded. This keeps packets from looping endlessly

. • Protocol-Indicates which upper-layer protocol receives incoming packets after IP processing is complete.

• Header Checksum help ensure IP header integrity.

 • Source Address-Specifies the sending node.

 • Destination Address-Specifies the receiving node.

WHY WOULD I NEED ROUTER:: ??

For most users, they will be setting up a LAN (local area network) or WLAN (wireless LAN) and all computers on the Internet without a full subscription service to pay their broadband ISP for each computer on the network. In many cases, an ISP you can use a router and several computers with a single Internet connection and a nominal fee for each additional computer sharing the connection. 

This is when home users will want to look at smaller routers, often called broadband routers that enable two or more computers sharing an Internet connection. Within a business or organization, you may have more computers accessing the internet, while even some private networks - and this is the kind of functions for a router design.

TYPES OF ROUTER::

Types of Routers There are different types of routers that you will want to understand. You should change to know that you can make your network or at least so you can understand the local computer guy told to do.

1>> BROADBAND  Routers::

  Broadband Routers can be used for different things.

 They can be used two different computers to connect two computers or to connect to the internet. They can also be used to make a phone connection to establish. If you have Voice over IP technology (VoIP), then you need a broadband router for your Internet connection to your phone. This is often a special type of modem that both Ethernet and phone jacks it.

 While this may seem a bit confusing, just follow the instructions that your VoIP provider sends your


2>> WIRELESS routers::

 - usually you need router to buy the company for the service you need. Wireless Routers Wireless Routers connect your modem and a wireless signal in your home or office. So any computer within range to make your wireless router and use your broadband internet for free.

 The only way to get someone to hold about your system, make sure your router. A word of warning for wireless routers: Make sure you secure them, or will be vulnerable to hackers and identity thieves. To secure your router, you just have to come in WhatIsMyIPAddress.com and your IP address gets. Then, you type in your web browser and log into your router (user ID and password will come with your router).

Remember router ID and password changes, and if someone else can lock you out of your system. Once there, go to wireless settings, enter a security key and you'll be about ready to go. Make sure you enter the key or storing it in a Word document.

 If you try to log into your Internet connection, you just need the key to enter. Your computer should be the key to remember, but write somewhere for safekeeping just in case.

WHAT IS ROUTER: ?

What is a router???

 Before we dive into the world of routers, you need to understand what a broadband connection is and how it works.

According to Dictionary.com, broadband is "a high speed, high capacity transmission medium that can carry signals from multiple network carriers independent This is done in a single coaxial or fiber optic cable through establishing different bandwidth channels..

Broadband technology can support a wide range of frequencies is used for data voice and video over long distances simultaneously broadcast .. "Routers takes the information received with the signal broadband via a modem to decode, and deliver it to your computer.

 Router will choose the best path for packet data so that you get information fast. Many different types of routers is designed to get information about your service can be delivered in a variety of different receivers, including your PC, your phone, and others.

INTRANET & EXTRANET &INTERNET ::

Is the difference between an intranet and the Internet: Internet an open, public space and interior is designed to provide a private space. Intranet can be accessed from the Internet, but as a rule, it is password protected and accessible only to employees or other authorized users .

From inside the company's intranet server responds much faster than conventional site. This is because the public Internet traffic is not radiation, the server crashes and other problems that slow the network's grace. Within the company, but users have more bandwidth and network equipment may be more reliable. This facilitates high-bandwidth content such as audio and video, to work inside ..

The term "intranet" is somewhat misleading conceptually, because it is contrary to the term "Internet". The real contrast is with the World Wide Web - an important distinction because the "Internet" focuses on the physical and technical networks, and online content focusing on a set of physical and technical infrastructure.

When I coined the term "intranet" at Amdahl Corp. in 1994 summer, it was not the tone of the internal web, rather than a single web. Indeed, the term we use internally that he was too clumsy for Enterprise-Wide Web. Thus, although the "Intranet" ambiguity, it was clear even in the absence of a better alternative, it is caught. ...

In the early days, I will define as infrastructure based on Internet standards and technologies that support sharing of a limited number of well-defined group, and intranet. "Infrastructure" refers to the organizational and management infrastructure in place, manage and share content. The only restriction is that the physical network based on the interaction protocol (IP). .

You may notice that this definition includes what we call the additional beautiful today as the decisive factor is the limited and well-defined group ", instead of what the official views of the organization. Web, by contrast, is a free group.

I think today, intranet, networks, and thus the contents of the collection online. Intranet content to determine the overall well-defined group within a single organization. extranet content of the general well-defined group, but one that crosses enterprise boundaries.

This is an important difference between the connection, a Web content by using the same technical infrastructure, regardless of the decision-making. This means that it is much easier to access the file contents are changing, as was his old world, something is often more accessible to a very successful effort involved.

technical infrastructure is fewer barriers to access specific content, it is important to note how, or if we want to limit access. the term 'intranet and extranet, as imperfect as they are, we provide a conceptual and pragmatic measures to discuss what we want select content available ...

These terms may be further changes to make sense. For now, the content of the collection, which is available to members of one body, intranet, even if the information travels over the public Internet infrastructure. ... 

PUBLIC AND PRIVATE IP ADDRESS::

Public and private IP addresses in order to maintain uniqueness within global space is the public IP addresses in Network Information Center (NIC) management of conflict avoidance.
Equipment in public should be identified as Web or e-mail, a globally unique IP addresses, and they are assigned a public IP address. Devices that are not public access node can be assigned a private IP address, and make it uniquely identifiable within an organization.

For example, a network printer assigned a private IP address for the world to stop its printing. Allow organizations to freely show private IP addresses, certain blocks NIC address reserved for private use. A private network is a network that uses RFC 1918 IP address space.

The following blocks are reserved for private IP addresses IP.


      Class                   starts IP                                     Ending IP address
               
                 

A	10.0.0.0	10.255.255.255
B	172.16.0.0	172.31.255.255
C	192.168.0.0	192.168.255.255

DYNEMIC AND STATIC IP ADDRESS::

Dynamic IP addresses are temporary and are given every time a computer to access the Internet. They are, in fact, borrowed from a group of IP addresses between different computers in common.

Since a limited number of static IP addresses available, many ISPs reserve a portion of their addresses assigned to the division between their subscribers in this way.

This reduces costs and allows them more subscribers in the service that they otherwise would. Static IP addresses are generally better for uses such as VOIP (Voice over Internet Protocol), online gaming, or any other purpose, users need to make it easy for other computers to locate and connect with them. Easy access can be facilitated when a dynamic IP address using a dynamic DNS service that allows other computers to find you even though you can use a temporary, single IP address.

 This often involves an additional cost, but so will your ISP.

WHAT IS LOOPBACK IP ADDRESS :: ?

 IP Address cycle is the use of self-earned.

 Name IPv4 loopback address 127.0.0.1 with a 255.0.0.0 subnet mask. A loop interface is also known as a virtual IP, which is not related to the hardware interface.

On Linux systems, loopback interface is commonly known lo0 check. Respective hostname for this interface is called localhost. Loopback address is used to test network software without physically installing a network card (NIC), and without physically connecting the drive with a / TCP IP network.

 A good example is the Web server running on ourselves to enter or http://127.0.0.1 using http://localhost.

WHAT IS MY IP ?

IF U WANT TO KNOW WHAT IS MY IP ADDRESS THEN PLEASE CLICK BELOW LINK::

http://whatismyipaddress.com/

IP ADDRESS ::

Home address & IP Address IP is an indication of a computer or device on a / TCP IP network. Networks using the TCP / IP protocol route messages based on destination IP address.

Format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.

Within an isolated network, you may want IP addresses at random as long as each is unique. However, connecting a private network on the Internet requires using registered IP addresses (called Internet addresses) to avoid duplicates.

 The four numbers in an IP address is used in different ways a particular network and a host on the network to identify. Four regional Internet registries - ARIN, RIPE NCC, LACNIC and APNIC - Internet addresses indicated by the following three classes.

Class A - supports 16000000 hosts in each of 126 networks

Class B - supports 65,000 hosts on each of 16,000 networks

 Class C - supports 254 hosts on each of 2 million networks

The number of Internet addresses assigned is running out, so a scheme CIDR Classless new branding is gradually replacing the system based on classes A, B and C and is associated with the adoption of IPv6...

WHAT IS DIFFERENCE BETWEEN LAN AND WAN AND MAN ?

A LAN (local area network) is a group of computers and network devices connected together, usually in the same building.

A WAN (wide area network) is not restricted to a geographical place, even though it may be confined within the borders of a state or country.

A WAN connects several LANs, and may be limited to an enterprise (a corporation or an organization) or open to the public. Technology is a high speed and relatively expensive.

 The Internet is an example of a worldwide public WAN.

A LAN (local area network) is ' A group of computers and network devices are connected, usually in the same building. By definition, connections with high speed and relatively inexpensive (eg, draw ring or Ethernet), to be. Most of Indiana University in Bloomington department LAN.

For more information on the LAN, see What is a LAN (local area network)?

 A MAN (metropolitan area network) is a large network, usually over several buildings in the same town or village. IUB Network is an example of a MAN ....

A WAN (wide area network), compared with a man, is not restricted to a geographical place, even though it may be confined within the borders of a state or country.

A WAN connects several LANs, and may be limited to an enterprise (a corporation or an organization) or open to the public.

 Technology is a high speed and relatively expensive. The Internet is an example of a WAN public worldwide ..

A LAN is a high speed connection in a LAN. In IUB campus, compounds are either Ethernet (10Mbps) or Fast Ethernet (100Mbps), and some countries have Gigabit Ethernet (1000Mbps) connections ....

 LAN (Local Area Network) is a network which has a small geographic area, like a home, office, or group of buildings of the Network in an organization can have a LAN typically owned, controlled and managed by a single person or organization is typically owned, controlled and managed by a single person or organization have LAN high speed data transfer Got a small geographic range and have no need for a telecommunication lines LAN employee may be used for other LAN is connected over a distance via telephone lines and radio waves WAN

WAN (Wide Area Network) is a computer network covering a wide area (eg, a link communication network among the metropolitan boundaries, regional, or national Internet is the best example of a WAN WAN (eg Internet) is not owned by any organization, but rather exist under a collective or distributed ownership management and technologies tend to wane as ATM, Frame Relay and X.25 use to access over longer distances eating has a lower data transfer compared to LAN Have a great geographic diversity across borders general and rental of telecommunications lines must

WHAT IS WAN ( WIDE AREA NETWORK )::

Definition:

 A WAN covers a large geographical area, as a province, state or country. WAN networks often several smaller, such as local area networks (LAN) or metro area networks (MANS). Most popular WAN is the Internet worldwide. Some segments of the Internet, such as VPN-based networks, WAN is also in themselves. Finally, many WAN is corporate networks, or research using leased lines. WAN typically use different and more expensive than LAN Network. Key technologies often include WAN SONET, Frame Relay, and ATM.

DEFINATION OF LAN:

Definition:

A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other as in an office building, a school or a home. A LAN is useful for sharing resources such as files, printers, games or other applications. A LAN in turn often connects to other LANs and the Internet or other WAN.

LOCAL AREA NETWORK:: < LAN >

A computer network that includes a relatively small area. Most LANs are confined to a single building or group of buildings. However, it can have a LAN connected to other LANs over any distance via telephone lines and radio waves.

A system of LANs connected in this way a wide-area network (WAN). Most LANs connect workstations and personal computers. Each node (individual computer) in a LAN has its own CPU with which it executed programs, but it is also capable of data and devices anywhere access to the network. This means that many users of expensive devices like laser printers, and data exchange.

Users can use the LAN to communicate with each other, sending e-mail or engaging in chat sessions. There are many different types of LANs Ethernets being the most common for PCs. Most Apple Macintosh networks are based in the Apple Talk network of Macintosh computers built.

The following features distinguish a LAN from another: topology: geometric arrangement of devices on the network. For example, equipment can be arranged in a ring or a straight line. protocols: The rules and encoding specifications for sending data. Protocols also determine whether the network uses a peer-to-peer or client / server architecture. media devices can be connected by twisted-pair wire, coaxial cables, fiber optic cables either. Some networks do without connecting media altogether, communicating instead via radio waves.

 LANs are capable of transmitting data at very fast, much faster than data can be transmitted to a telephone line, but the distances are limited, and there is a limit to the number of computers which can be for a LAN single attached.