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Computer Networking
Computer networks are collections of computers which are connected together in order to communicate and transfer information. Questions about computer networks, networking protocols, and how to set them up belong here.
18,810 Questions
What is the purpose of public IP address?
the main purpose of ip address is to know the location of particular file as much as possible
Is there any game where you can have kids or be a kid?
yes its called "sims" and its a well known and very popular game in many country's
ADSL (asymmetrical digital subscriber line)
is a protocol that you ISP (internet service provider) use it is a analogue signal.
cable normally is a cat 5e or cat 6 in to the modem and is a digital connection (much faster)
These are hard numbers to nail down, as you had to also purchase licenses for client access. Depending on the edition and number of licenses, the price ranges from about $299 to over $6,000. Different stores could (and still do) charge higher or lower prices for retail and OEM copies as well.
Should computers on a network have the same subnet mask?
Subnet mask defines our network bit . If we are using a single network then all computers should have same subnet mask as well as the ip address, that belongs to the same network id.
- A Local Area Network is a small network which is usually contained within one building or campus. It is usually a private network, unlike the public internet. An Administrator in charge controlls file sharing, access and many other factors. LANs can be connected to public networks like the Internet, with some precautions (against hackers, viruses etc). Usually a firewall/proxy server/router acts as the gateway between the LAN and the Public Network. A popular wired LAN technology is the Ethernet (Sometimes called IEEE 802.3). These days Wireless LANs are becoming popular. They are collectively known as IEEE 802.11 LANs.
- I could spend hours going into detail about this question, but I won't. Basically the proxy server will go to internet to pull a webpage for the client requesting it. It also will store a copy of this page (cache) for future requests. Another function of the proxy is that is hides the clients IP address from the "outside world", and uses its own. Therefore, the webmaster of the webpage cant see the IP of the client requesting the page because in actuallity the proxy is requesting the page.
LAN
lan stands for the local area network .ie if you are connecting you comouter or devices (printer ) in a specific limited area ie locally .
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A LAN allows certain computers on the network to offer their resources (hard disks, floppy disks, CD-ROMs, Printers, Modems, etc.) for use by other computers on the network as if they were their own. Computers that offer resources are called Servers.
Computers called Workstations can attach the resources (typically hard disks and printers) offered by servers as if they were their own. For instance, at AA Company, computer #1 has a C: hard disk and a D: CD-ROM. Computer #2 has a C: hard disk and a D: CD-ROM, but computer #2 also attaches computer #1's C: drive as it's own F: drive. To the user of computer #2 it looks as if drive F: is in his own computer. He can use files and programs from the F: drive just as he can from his own C: drive. The network software module that performs this slight of hand is called the redirector.
A computer can be both a Server and Workstations at the same time, in which case it is called a Peer. Networks without dedicated servers are called peer-to-peer networks. Networks with one or more dedicated servers are called server based networks even though they may also have peers on them.
Back to our example. The network computers #1 and #2 are on has a server, computer #3. Computers #1 and #2 each have a copy of an accounting program on them, but both read and write accounting data to their G: drive, which is actually C: on computer #3. The tape backup unit is on computer #3 and backs up all the accounting data for all the computers every night by backing up its own C: drive.
When computers #1 and #2 are using the accounting software that software is running in their own memories. The server is not involved at all except to offer its hard disk for data storage. This server is called a file server.
Since this is a Windows accounting package it is big and slow and swaps to disk a lot, so each computer has it installed on its own hard disk to get decent performance. In the days of small fast DOS programs, workstations would also load the program from the server, so it only had to be installed once in one place.
When computers #1 and #2 do sorted reports, every record has to be read from the server and sorted in the memory of the workstation and written back to temporary files on the server. This causes a lot of network traffic on a larger network.
Lets say AA Company grows a lot and now still has computers #1, #2 and server #3 but has added additional workstations #4 through #29 - and lots of users of the accounting software. all that network traffic causes the network to get really bogged down and users start to complain.
What AA Company does now is ditch that Windows accounting package and install a new multiprocesor Compaq server running Windows NT. The new accounting package uses the Oracle database program to store its data at the server. This new package actually runs on the server (which is now called an application server because it has applications programs running on it). The workstations just have a client program that asks for records and has input and viewing screens. If a client asks for a sorted report all the work is done at the server, cutting network traffic way down. This is called a Client Server network.
Meanwhile, across town, BX Company started with its accounting on a Xenix host computer with some "green screen" terminals wired to it (instead of PCs like AA Company used). There was no network at all, just a lot of serial cables connecting dumb terminals and printers to the host computer.
As it grew, BX upgraded to a Unix host computer and added some PCs that were also wired back to the host and ran terminal emulation software so they could act as terminals to use the accounting. Some of the PCs also got their own printers, which also act as slave printers to the Unix box. Still no network.
Finally, BX Company needed to exchange marketing and project files among the PCs, so they installed a peer-to-peer network connecting all the PCs, and included their big honk'n Sun Enterprise Unix box in the network too. The PCs dumped the terminal emulation package and use telnet which allows them to act as terminals over the network - no more serial cables. Later they add a Linux box to the network to act as a file server, as an Intranet Web server and as a firewall for their DSL connection to the Internet.
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ANSWER
LAN is a Huge topic and to know how it works you need to understand what it features are and in what ways a LAN can work like it can work in a Ring Network,Bus Network...It can be used With WAN from a larger to cover a small area,The transmission can be provided by the Token Passing Technique or the Carrier Sense Multiple Access/Collision Detection Technique...The OSI Layers...The hardwire and the software Required...and so On.
I think you can start from the basics to have a better understanding and don't miss out anything.Search in Google or better buy a Book on Networking.
What is mean by Fragmented Packet?
Background: everything that is sent over the Internet is sent as small messages, known as Internet Protocol (or IP) packets, that are in a common format regardless of the kind of link over which the packet is currently being transmitted.
In version 4 of the Internet Protocol (which is the version that is most widely used today) a packet may be too big for the kind of link over which it is about to be sent. For instance, traditional Ethernet imposes a maximum size for IP packets of 1500 bytes. If a packet that is about to be sent over an Ethernet link is bigger than that, the router which is about to send the packet over that link will fragment the packet. What this means is that the router will split the packet up into smaller messages (known as fragments) that are each small enough to be transmitted over the link. When the fragments arrive at their destination (the computer to which they are being sent), that computer can reassemble the fragments to recover the original message - assuming none of the messages are lost in transit.
IP version 4 also has a "don't fragment" option which tells routers to not fragment packets that have that option set. If this option is set, and the router wants to send the packet over a link for which the packet is too large, the router will not send the packet at all. Instead, the router will send a message back to the sender of the packet that was too large. The sending computer can then respond to this by sending out smaller packets. This is known as "path MTU discovery" because it enables the sending computer to determine the largest packet size that will work for the path between sender and receiver. (MTU stands for maximum transmission unit.)
For best efficiency the sending computer would like to send out packets that are as large as possible, but not so large that any of the packets will be fragmented.
Fragmentation is of dubious value because it slows down routers, and because none of the fragments will be useful to the receiver computer unless all of the fragments arrive there intact. Path MTU discovery is generally considered preferable to fragmentation. However there are problems with Path MTU discovery. One is that many sites (for no good reason) filter the messages that are sent back to the senders when a packet is too large for a link. Another is that path MTU discovery is inefficient for short conversations consisting of just a packet or two in each direction. Yet another problem is that the path between sender and receiver can change during a conversation in a way that renders the old path MTU obsolete.
Internet Protocol version 4 (IPv4) is in the process of being supplanted by Internet Protocol version 6 (IPv6). In IPv6, routers do not fragment packets, and path MTU discovery is mandatory.
What do I need to set up kitchen and bath supplies in a first home?
The supplies needed to set up a bathroom and kitchen are your everyday necessities. You need things like bath towels, hand towels, dish towels, dishes, dish drainers and pots and pans.
What is the difference among different types of switching devices in networking?
Switches are data link layer devices that, like bridges, enable multiple physical LAN segments to be interconnected into a single larger network. Similar to bridges, switches forward and flood traffic based on MAC addresses. Any network device will create some latency. Switches can use different forwarding techniques-two of these are store-and-forward switching and cut-through switching. In store-and-forward switching, an entire frame must be received before it is forwarded. This means that the latency through the switch is relative to the frame size-the larger the frame size, the longer the delay through the switch. Cut-through switching allows the switch to begin forwarding the frame when enough of the frame is received to make a forwarding decision. This reduces the latency through the switch. Store-and-forward switching gives the switch the opportunity to evaluate the frame for errors before forwarding it. This capability to not forward frames containing errors is one of the advantages of switches over hubs. Cut-through switching does not offer this advantage, so the switch might forward frames containing errors. Many types of switches exist, including ATM switches, LAN switches, and various types of WAN switches. Asynchronous Transfer Mode (ATM) switches provide high-speed switching and scalable bandwidths in the workgroup, the enterprise network backbone, and the wide area. ATM switches support voice, video, and data applications, and are designed to switch fixed-size information units called cells, which are used in ATM communications. Figure 4-3 illustrates an enterprise network comprised of multiple LANs interconnected across an ATM backbone. Figure 4-3 Multi-LAN Networks Can Use an ATM-Based Backbone When Switching Cells
LAN switches are used to interconnect multiple LAN segments. LAN switching provides dedicated, collision-free communication between network devices, with support for multiple simultaneous conversations. LAN switches are designed to switch data frames at high speeds. Figure 4-4 illustrates a simple network in which a LAN switch interconnects a 10-Mbps and a 100-Mbps Ethernet LAN. Figure 4-4 A LAN Switch Can Link 10-Mbps and 100-Mbps Ethernet Segments
there is no figures as noted above
To get "wireless" access from a cable modem, you will need a wireless router in addition to the cable modem.
Wireless routers are made by Linksys, and a number of other vendors.
Start:
1. Plug the coax cable from the wall into your modem. (this is the "live" internet connection now powering your modem. The modem is now "live")
2. Run the ethernet cable from your modem into your wireless router. (this router is now "live")
3. Run the ethernet cable from the wireless router into your PC. (the PC is now "live")
You are basically looping the modem into the router, and the router to your PC, instead of going directly from the modem into the PC. The benefit of looping the wireless router in between the Modem and the PC is so that the wireless router can get a live internet signal and broadcast a "wireless" signal to your home and surrounding 100 foot area.
The reason you loop the ethernet cable from the wireless router (in step #2) back into your PC is so that the PC can get the internet connection. Most PC's don't have a wireless "receiver" to receive the wireless signal, and require a direct input from an ethernet cable.
Most laptops have wireless ("receivers" aka: modems) and can receive the signal from the wireless router (which is now actively receiving and broadcasting the signal) which we connected in step #2.
The concept is very similar to your home telephone with a wireless handset. The phone line runs into the base station, and you can walk around your home with a wireless phone. This is the same with your laptop, and the wireless router is just like the base station of your phone.
What is the Unit for Dispersion in optical fiber?
unit of dispersion is:
(picosecond)/ nanometer kilometer
Which are the two protocols associated with layer 4 of the OSI model?
There are actually more than two protocols associated with Layer 4. According to Wikipedia, there are Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Stream Control Transport Protocol (SCTP), Datagram Congestion Control Protocol (DCCP), and Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX).
For what nodes would it make the most sense to assign a static rather than dynamic ip addresses?
1. B - The laptop used by a salesperson while traveling
The exit interface configuration consumes less router processing time
Dimana komputer digunakan secara besar-besaran?
Perusahaan multinasional menggunakan komputer dalam skala besar. ini dapat melibatkan genggam, laptop, desktop, dan komputer mainframe
What ports on a laptop are serial ports?
Many modern laptops don't have a serial port at all. The most common serial ports on desktop computers were the old style of mouse ports that look like this picture:
http://i32.tinypic.com/29vtir.jpg
What does the Data Link layer use to find hosts on a local network?
ARP - Address Resolution Protocoll. Gets the corresponding MAC to an IP.
RARP - Reverse Address Resolution Protocoll. Gets the corresponding IP to a MAC.
The protocoll uses broadcasts and works only in the local network.
How much does it cost to setup a server for 1000000 computers?
It would cost approxamitly $40,000 including the price of the server(S)
What are the problems that can occur when data is transmitted across a communication link?
The foremost problem that can occur is the "loss of data" due to interference or the data collision that causes corruption of data...
How do you play online without internet?
You can't get online without the internet. You can get free Wi-Fi at locations such as hotels and restaurants, you can also go the the library. Many ISPs also offer free dial-up.
What step is this dhcp discovery dhcp offer dhcp request dhcp acknowledge?
Those are the four phases of acquiring an IP address via DHCP. More information would be needed to indicate which of the 4 phases are being used at this point.
How Cisco network academy practical exam final 1-10?
Cand instaleaza o placa de retea in calculatorul unui client, un tehnician observa ca trebuie curatate contactele adaptorului. Ce solutie ar trebui sa foloseasca tehnicianul pentru a curata contactele?
Solutie pentru curatarea geamurilor
Alcool izopropil
Detergent slab
Alcool medicinal
Lichid de curatare usor abraziv
