Computer Networking

First, convert the relevant portion of the subnet mask to binary: 255.255.255.1110 0000[1], aka /27. Next the last octet of the IP address (slightly more complex, but 5's an easy one): 0000 0101.

That means the network is 123.123.2.0/27, the all-host-bits-1 broadcast address is at 123.123.2.31, and available host addresses are 30 hosts from 123.123.2.1 to 123.123.2.30 .

[1] I skipped the all-ones octets, because they're not really necessary to write out.

If you want it slightly more expanded:

Subnet mask: 1111 1111.1111 1111.1111 1111.1111 1111.1110 0000
IP address: 0111 1011.0111 1011.0000 0010.0000 0101

Network address: 0111 1011.0111 1011.0000 0010.0000 0000

For each bit of the subnet mask that is 1, you take the equivalent bit out of the IP address, and the rest you fill with 0. If you prefer that terminology, you perform a bitwise AND of subnet mask and IP address.

Broadcast address: 0111 1011.0111 1011.0000 0010.0001 1111

For the broadcast address, take the network address and fill the host bits with 1s instead of 0 (this is why they're also called all-0s and all-1s respectively).

Now just convert that binary broadcast address back to decimal: 123.123.2.31
(ProTip: You already know three of those octets because of where you got them from.)
(ProTip: a nibble filled with 1s is 15 or 240 decimal, and a nibble filled with 0s is always 0)

When you have the network address and the broadcast address, you also know the available host range for this subnet: one inward from each end, or 123.123.2.1 to 123.123.2.30 .

Ring topology is a setup in which the systems are connected to their adjacent systems directly....if a system wants to connect / communicate with a farther system....it sends the data through the different systems on the path, so, there is very less security of data and encryption algorithms are the only way to protect the data

wi-fi metwork or wlan ...!voila ! i approve that one too !

most technicians and other people refere to it as a "nic"

bus topology.

You'l need 5 4 to 1 muxes for making a 16 to 1 mux if your inputs are say W(0)-W(15) i.e 16 inputs ..... you start of with giving 4 inputs each to the 4 to 1 muxes the select lines for all 4 4 to 1 muxes will be common now each of the four 4 to 1 muxes is giving you one o/p so ..... take each of those 4 outputs and give them to the fifth 4 to 1 mux and voila you have a final o/p corresponding to 16 inputs !!! THIS IS HOW IT WILL LOOK LIKE inputs outputs mux 1 : w(0)w(1)w(2)w(3) m(1) mux2 : w(4)w(5)w(6)w(7) m(2) mux3 : w(8)w(9)w(10)w(11) m(3) mux4 : w(12)w(13)w(14)w(15) m(4) taking the above 4 outputs and giving them 2 mux5 mux5 : m(1)m(2)m(3)m(4) m(5) m(5) is the final output corresponding to 16 inputs W(0)-W(15)

In computer networking there is a seven layer OSI model and the LLC or logical link control layer is a data communication protocol layer which is the upper sublayer of the second OSI layer known as the data link layer. The main characteristic of the LLC sublayer is that it provides multiplexing mechanisms that allow for a number of different network protocols like IPX, AppleTalk and IP to work over the same network as well as allow them to exist together within a multipoint network.

ospf protocols is used back bone router

Network + Guide To Networks Review Question Chapter 6 #20

NO it is BGP, answer on page #280 it is in the definition

Fibre optic cables are used to transmit data using light rather then electricity. Because there are many colours of light, fibre optic cables are very effective medium for this, they can transmit allot of information at once.

The maximum length of a segment is usually 100 meters. In practice, it's a good idea to stay under 90 m for fixed cables, since patch cables at either end are likely to add another several meters to the overall length.

The major disadvantage of fiber optic versus metal cable is that it is difficult to make connections to fiber optic cable. Single-mode optical cable (the type used for communications) has a core as fine as a human hair (although the entire fiber is thicker). When making splices, the fiber cores must be perfectly aligned. Also, the ends of the optical fiber must be highly polished to allow light to pass with little loss. There is also the problem of converting back and forth from a light signal to an electrical signal. However, the advantages of fiber-optics far outweigh the problems. One single mode fiber can replace a metal cable that is thousands of times larger and heavier. Multi-mode optical cable has a larger diameter and can be used to carry signal over short distances.

A wireless router provides a wireless network, but does not provide Internet connectivity by itself, unless it is a combination router/modem, such as a Motorola Surfboard. A typical home wireless router will not have this functionality included, so a cable modem is often required to access a cable provider's Internet service. Buying a device that includes both wireless routing and cable modem features will allow the network to access the Internet without a dedicated cable modem, while all others will require a cable modem separately. In either case, a device that provides the features of a cable modem is required for cable Internet.

TCP has no default port. Individual applications - such as FTP, DNS, or Telnet - do have default ports.

An internet speed of 100 is fast if it refers to megabits or gigabits per second. If it is a 100 kilobit per second connection, it is very slow and only twice as fast as dial-up.

An input device is any peripheral used to provide data and control signals to an information processing system ... examples - mouse, keyboard

An output device is any peripheral used to communicate the results of data processing carried out by an information processing system ... examples - printer, monitor, speaker

if its windows xp right click on my computer, then select properties, then click on computer name tab then on the network id button and change the workgroup in the workgroup box. Any computer you want to be in the workgroup you need to make sure all those computers say the same thing

is a service that converts ordinary text email into phone voice messages. Like ordinary email, the eMail2Phone.net phone voice messages are highly interactive and you can hear, reply-to, save, delete, skip, and send these messages. '''eMail2Phone.net manages these email-to-phone voice messages in two ways:''' * Outbound - Email messages that are sent to your phone as high-quality, phone voice messages. * Inbound - Email messages that are retrieved as phone voice messages when you dial into the eMail2Phone.net system.

Regardless of the size or number of employees, every company experiences problems at some time or other. Anticipating the most common problems ahead of time and working to avoid them is the best way to reduce calls and ensure a smooth daily experience. Quite often, when that phone does ring, the problems tend to be the same, since there are some very common problems that can present themselves in any environment that utilizes a networked system.

One problem that may arise is the issue of a duplicate IP address. This is, quite simply, the address that the network uses to identify a specific computer. Every PC - and laptop - possesses a unique IP address, but sometimes two will receive the same one as the result of an error. When this happens, communications problems arise and the Systems Administrator or Network Engineer will need to change the address on one of the computer terminals in order to fix the problem quickly and easily.

Connectivity issues are among the most common problems that are brought to the doorstep of the systems department of a company. This can be caused by a number of things, including configuration changes or the malfunction of connectivity devices, such as in the case of a hub. The first thing to do, of course, is to check your physical connections. If something is disconnected, you'll need to reconnect and test it in order to make sure that the problem is resolved. If all physical connections look to be in place, check that the port on the hub to which the cabling is connected is on and working properly. There should be a green light on at the port site which indicates that the port is live and ready to connect. Similar can be done with switches and . If these look to be stable, then check the configuration of the equipment that's experiencing the problem. It could well be that it simply needs to be reconfigured to accommodate the type of equipment that's been attached to make the

In the same spirit, there are sometimes simply problems with the physical cables that connect various types of computerized equipment. Sometimes these physical connections become broken, severed or simply short out. In the case of an electrical short, this can happen when the conductor comes into contact with an outside source that also serves as a conductor. This will reroute the signal and cause networking and/or other electrical problems. In order to correct these types of problems, check to see if the physical connections have been compromised. If so, these can easily be changed, or new wiring can be manufactured with the proper connections by the staff members of the systems department. If nothing appears to be physically disrupted, then cable testers can be utilized to test for other types of electrical and networking problems. These include connection problems, electrical shorts in the cabling, incorrect cable connections and the interference level, in the case of a signal disruption due to diverted conductor paths.

Software problems can be the cause of networking problems, as well. When all of the physical possibilities have been eliminated, you'll need to look to the actual system to discover what the cause of the problem may be. A variety of configuration problems may be at the root of the situation, such as those of the WINS or DNS variety. Registry problems may also cause a networking issue, as well as a number of other software-related possibilities. Depending upon the cause of the problem, you'll need to either make configuration changes or, perhaps, reinstall a specific piece of the software that may have malfunctioned.

If you should find that your connectivity is unusually slow, this may be a sign of excessive network collisions. This is sometimes the result of a network that's been poorly planned or mapped out, or of a user transferring an inordinate amount of information at one time, which floods the network. There are options for transferring data without putting undue pressure on the system, such as in the case of word processing documents that are bulky. These can be sent as zipped files, which will send the information without violating any of the data, yet relieves the network of the amount of pressure that it would have taken to transmit the data if it hadn't been zipped. A jabbering network card - a network card that's stuck in the transmit mode - can also cause excessive network collisions. You'll be able to recognize this because the transmission light will remain on continuously, which literally means that the network card is transmitting on a nonstop basis. This can be alleviated by replacing the necessary components and testing them to be sure that the problem has been eliminated.

There's a way to combat any networking issue - it's just a matter of being prepared and knowing what the most common problems are, so that you'll have the necessary tools at hand to make whatever corrections are needed as smoothly and quickly as possible.

VPNs

Check that other computers connected wirelessly to the router have internet. If with internet on other computers everything is ok, check router mac filter. Check firewall settings on your laptop. Try to turn windows firewall off and connect to internet. If it works you have to create manually rules for the firewall in order to use it along with internet. Check your broweser settings such Proxy servers, coneection, network and so on, check your PC on another router (some adapters are not compatible with certain routers).

Technically, there is no limit to the size of a p2p network.

A packet may be lost due to congestion: too many packets are sent, the queue gets full, and eventually the router or switch starts dropping packets. It may also occur due to different failures; including temporary cabling problems, problems in a switch or router, etc.; these in turn can cause temporary problems with the routing information (a "non-converged network"), causing the packets to travel in loops until the TTL runs out, or a router erroneously concluding that a certain address can't be reached. This latter problem might also be caused by a misconfigured router.