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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
Who can own a class b Ip address license?
Large organisations that can use around 65000 ip addresses however they will usually waste around 75% of these
When would you need to use a wireless access point WAP?
You need a wireless acsess point when you have a device that you want to connect to the Internet and you do not want to use a twisted pair network cable to do that.
cisco material :periodic challenges to make sure that the remote node still has a valid password value. The password value is variable and changes unpredictably while the link exists.
A challenge message is sent to the peer router, which responds with its username and a calculated value based on a shared secret. This value is then compared by the challenger to its own calculations.
What are the three router roles in an OSPF network?
Designated router, the backup designated router, and the DROTHER
Internetworking with Cisco and Microsoft Technologies pg. 306-307
event viwer
What is the subnet mask of ip 192.168.0.5?
it is a class c address..so default subnet mask is 255.255.255.0
it is a private address...
What causes attenuation on wireless signals?
Attenuation limits the range of radio signals. Wireless signals are radio waves. Like any type of electromagnetic radiation, they are subject to attenuation. Attenuation normally includes propagation losses caused by the natural expansion of the radio wave front in free space (which usually takes the shape of an ever-increasing sphere), absorption losses (sometimes called penetration losses), when the signal passes through media not transparent to electromagnetic waves, diffraction losses when part of the radio wavefront is obstructed by an opaque obstacle, and losses caused by other phenomena.
Propagation losses become worse as the distance between the source and receiver increases. Just like a light source becomes less intense to the observer as they move away from the light, the radio signal becomes more faint as the receiver becomes more distant from the signal source. Distance is thus an attenuating factor for all wireless signals.
Absorption losses occur when some of the signal is absorbed by the media between the radio signal source and the receiver. All types of electromagnetic radiation is subject to this kind of attenuation as well: sunlight is attenuated by dark glasses, X-rays are attenuated by lead, and light is attenuated while passing through seawater. For radio waves on earth (where wireless computer signals are important), the primary "medium" air and attenuation is an exponential function of the path length through the air. Attenuation is also affected by all the materials a signal must travel through including not only air, but building materials (e.g. wood, concrete, steel, glass, etc.) if the wireless connection is made within a building and weather when the wireless signal is traveling outside the building (e.g. rain, sleet, snow, fog, smog, smoke, etc.). Each medium soaks up different amounts of radio energy. Metals tend to be the worst. It is possible to build what is known as a Faraday Cage that will shield radio signals almost completely by absorbing them and conducting their energy away to "ground".
Some materials block radio signals almost completely even if they are not grounded. Even if they block them, they may still reflect some of the radio waves off in another direction causing interference or simply lengthening the effective path the waves must travel between the source and receiver. If the radio-opaque material has gaps in it, some of the signal may still leak through, but less than the amount that ran into the barrier. A simple analogy would be a screen that lets most of the light through but blocks some of it, lessening the intensity of the light that does make it through. Another analogy would be polarized sunglasses that only pass the light that is vibrating in the direction of the polarization.
MX records.
What are the two layers of osi model in ccna?
There is no two-layered OSI model in CCNA.
7-layer there is (physical, link, network, transport, session, presentation, application).
4-layer there is (physical, network, transport, application), being the first an abstraction of physical+link and being the last an abstraction of session, presentation and application. This model is used because of the CCNA point of view, having no relevant meaning the abstracted layers.
How do you out source our mail server?
The mail server can be hosted using Windows or Linux. If the mail server is for a small business, there is no need for a dedicated exchange server for a Microsoft platform. When there is website is hosted for the company, the email accounts are part of the deal, when it is hosted with ISPs. Also spam and anti-virus check can be done at the ISP mail exchange level at a small fee annually.
What is difference between protocol and report?
the two are not synonymous .
you cant compare them
Think of a protocol as a set of rules.
DMZ
As determined by DOD Wireless regulations classified data may be transmitted wirelessly but only under strict and secure deployment configurations and approval from the conditions for transmitting classified data per DAA approval.
If you are using firewall can you access your router settings in order to find your wep key?
Yes, if your firewall has allowed connections from the router then you can find the IP. I am assuming you are using Windows you can open command prompt > type 'ipconfig' > then find the IP for the router.
Then in your address bar in a web browser paste this IP in.
It uses ICMP protocol - Internet Control Message Protocol
How do you find the address of your school server network in the summer?
If the school has a website you can do a DNS lookup on the site. That is if the site is located at the school.
Which layer does token ring works?
Token ring local area network (LAN) technology is a protocol which resides at the data link layer (DLL) of the OSI model.
It strictly depends on your environment and cannot be easily calculated. You need basically go around and see how far your wireless routers cover the area.
Why it is named as high speed networks?
The speed of data transfer (in KBps or MBps) between computers connected in these networks (Internet, LAN or WAN) will be faster than normal networks. Hence they are called High speed networks. Here high speed Swithing facilitates high speed data transmission.
How far can RG-6 cable be laid without losing signal strength?
RG6 is a co-ax cable commonly used for RF frequency signal transmission in applications such as satellite dish and aerial down leads. There are losses with any signal transmission in wires so signal strength will be reduced for any length of cable. The loss of the signal depends largely on the frequency of the signal and to a lesser extent, the resistance of the cable. The losses that are seen are normally of no significance as long as the receiver is presented with a signal of sufficient magnitude and quality to be able to interpret it correctly.
RG-6 is now not a supported specification. RG-6 cables can vary in performance between one manufacturer and another.
Additionally, the receiver circuitry can play a significant part in the total line length that can be used.
It is impossible to offer a definitive answer to the question because there are so many variables. If there are concerns about the length of the cable run it may be worthwhile to consider larger diameter cables that exhibit lower losses than RG-6. A local satellite or aerial installer will probably be able to ask the right questions and offer a practical solution.
