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Local Area Network
Questions concerning the setting up, troubleshooting and operation of wired LANs used by businesses and other organizations
4,003 Questions
Software trends in client server computing?
In order to stay abreast of the new trends in Client-Server, we must start by looking at what is happening in the software trends as a whole. In the 1960s and 1970s was the era of centralized computing, with IBM mainframe occupied over 70% of the world's computer business. Throughout the 1980s, many functions once performed by the omnipresent IBM behemoths were systematically taken over by PCs. The result of this gravitational shift toward personal computers makes two significant remarks on the computer industry:
The PC shift made corporations to reset their IT organizations in a number of ways. We are currently in the Client-Server phase of the software development and will eventually move towards the truly distributed computing environment. In IT manager's point of view: distributed computing can be used as a tool for business process reengineering, corporate right-sizing, and customer responsiveness. The new software developments can be characterized as follows:
- Distributed: The main operating force in the software industry is the drive toward distributed computing, currently in its Client-Server phase.
- Multiphased transition: Client-Server is merely an intermediate step toward distribution. The ultimate goal is collaborative computing based on peer-to-peer networks.
- Enabling technologies: Prominent supporting technologies are object-oriented components, document-centric software architectures, data warehouse technology, standards, and the end-user programming trend.
On the other hand all the above software developments cannot afford to become set in its ways and without taking considerations or meeting the business needs as follows:
- Isolated desktop software solutions are no longer sufficient. The software industry must respond to consumer demand for portable, interoperable, distributed software solutions or else becomes extinct like their mainframe-only predecessors.
- Open Systems for Computing: the pressure on software vendors to establish interoperable, distributed, easy-for-end-user-programmers-to-use tools and standards upon which enterprise-wide architectures can be built.
-Business process reengineering increased consumer expectation, and networked distributed hardware, as well as numerous second-order complications are driving software complexity through the roof.
The software industry will, out of necessity, respond to the above pressures by forming forums, consortia, and back-room alliances in order to establish market-leading architectural infrastructure standards, interfaces, and middleware for the express purpose of shifting the balance of power in favour.
Why you use VLAN if you can separate the network by giving them different IP and subnetmask?
Good question - I think the best reason is that you can move nodes between networks by changing the configuration at the switch. With different subnets you may have to physically move the device to get it into another subnet.
How do nodes in a 10base5 network attach to the backbone?
To connect a node to the wire, an Auxiliary Unit Interface (AUI) is used from the node to a transceiver. The transceiver is attached directly to the wire.
Internetworking with Cisco and Microsoft technologies, pg. 228
Does the data link layer finalize and frame a packet?
yes,data link layer finalize and frame a packet as frame is a series of bits that units a data.........
When the host portion of an IP address is all binary ones?
The host portion of an IP address of all zeros indicates that you are referring to 'this network'. For example, the address 145.5.0.0 means the network 145.5
Is the default gateway address a portion of the destination IP address?
No, it is not. A destination IP address may be any address, usually on a completely different network. The default gateway address is used to determine where to send packets that need to be routed outside of the current local area network.
Dynamic IP assignment means that your IP address can change.
FIR
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.
Check to see if your router has a 'reset' button. This button usually resets the router to the default factory configuration. Of course, it is best to have the user's manual when doing this so you know how to reconfigure the router.
- 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.
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).
Where is the security key on a comcast modem located?
The security key on a Comcast Modem is located next to the serial number of the unit. Sometimes the serial number is the number used as a security code if it is not printed on the device.
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 does NAT allow private addresses to communicate over the internet?
NAT or Network Address Translation actually comes in several flavors. Simply NAT and NAT PT (Port Translation) are available in both IPv4 and IPv6.
NAT uses a router or Integrated Service Router to translate your private IP address to a public routable address. Most home DSL or cable modems provide NAT services. 192.168.0.0 through 192.168.255.255 are defined as private addresses or "Not routed over the Internet" addresses. There are other ranges such as 10. which won't be not routed over the public Internet
What NAT does is translate your private addresses to a public address or list of possible public addresses. PT which is sometimes referred to as port overload will send request using the same public address by associating the private address with a specific port.
Simply this means that even if only one public address is available many private requests can be serviced by assigning and then tracking a port assignment at the NAT point of service.
So if two NAT/PT serviced hosts both request different HTTP page downloads on the same public address each is assigned a different TCP port. When the request return they are routed to each private address based on the port number. Cool how it works.
This is not the same as proxies so don't get confused.
Why is there no need for csmacd on a full-duplex ethernet lan?
With full duplex communication, there is no need for CSMA/CD because it is possible to send and receive data at the same time. It's only with half duplex communication that this would be needed.
How does the data link layer prepare packets for transmission?
It encapsulates with a header and a trailer to create a frame.
Where should 16-year-olds be looking for work in the local area?
sixteen year olds can look for work at fast food restraunts, skating rinks, bowling alleys, retail stores like walmart or target, and at the mall.
tunneling
Which type of network sends data only to the device specified as the destination?
Though this question is pretty ambiguous, you probably mean NBMA networks (Non-Broadcast Multiple Access).
What is the use of paged memory?
Paged memory is used to extend the real physical memory of the machine by copying blocks of data from the memory to a drive. That way you can run many programs simultaneously even if they consume more memory than you physically have in your computer. When a program requires to access the data that is "paged to disk" the operating system will read this data into memory.
