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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 difference between port filtering and port forwarding?
There is no difference between port mapping and port forwarding and both are equal and in some router they are used instead of the other one .
The meaning of these names is that "New connections from the outside to a certain port or port range go to a designated LAN machine. The ports are determined by the kind of server you want to run, (e.g. 80 for a web server) and the IP is the private LAN IP of your web server."
What is the maximum allowable segment length on a 1000base t newwork?
The range is effectively unlimited because multiple active components can extend the range to nearly any range.
Name two situation in which a crossover cable would be used to connect devices?
A cross-over cable is used to connect two computers together without the use of a connecting device, such as a switch or hub.
When daisy-chaining hubs and switches, some older equipment has a special port called the up-link port. This port requires the use of a cross-over cable to add hubs to hubs, etc.
LAN (Local Area Network)
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What is frequency in data communications?
If you're talking about electronic communication, both analog and digital communication use a "carrier" frequency to send data. Voice can be across a wire without a carrier, but it's not very efficient. When a carrier frequency is used, the baseline frequency or amplitude can be modulated to transmit the data. In the case of a digital signal, the computer is watching the pulses. any anomaly in the pulses that are expected at a specific time can be converted to data. Data is validated using checksums and parity.
The telephone line the bandwidth for the voice is usually the bandwidth for data?
Because voice communication uses more information to reproduce the person's tones and qualities over the line. Data is a digital signal composed of 1 & 0 - needing much less bandwidth.
What port does DNS operate on?
Strictly speaking, the question is invalid, as DNS uses both UDP and TCP for its transport.
The expected use is for DNS to run on top of UDP, with a fall-back to TCP for data packages that can't fit into a single 8K UDP packet. Large replies and zone transfers will fall in to this category. DNS can also be configured to work exclusively over TCP, but this isn't recommended.
Early MS Windows systems used DNS over TCP exclusively. Fortunately the more recent editions (XP onwards) use DNS over UDP by default, falling back to TCP only when necessary.
Why UDP rather than TCP? It's simply a matter of efficiency. To start a TCP connection a minimum of three packets are required (SYN out, SYN+ACK back, ACK out). By the time you add a data packet into that and close the session off correctly you will have sent several packets. In contrast, UDP can get away with a minimum of two packets (one question, one reply).
DNSSec adds a layer of complexity to this, but with caching the extra resource required can usually be mitigated against a number of queries.
Why does a switch offer better security than a hub?
b. A hub forwards data it receives to every device connected to the hub. It is possible for a network devices to pick up data intended for a different device. A switch eliminates this by only forwarding data packets to the correct device whenever possible
How would you instruct a Linux system to use the local network's DNS cache located at 192.168.1.254?
If your linux box acquire address automatically from your router then your computer already is using dns cache located at your router. Router is in almost all cases already using ISP DNS.
If you use static IP and some different DNS and you want to change it back to 192.168.1.254 you can use it probably through Network Manager. Most linux distribution has one.
Example for Ubuntu
Click System menu, click Preferences, then click Network Connections. Select the connection for which you want to configure local DNS.
For example:
To change the settings for an Ethernet connection, select the Wired tab, then select your network interface in the list. It is usually called eth0.
To change the settings for a wireless connection, select the Wireless tab, then select the appropriate wireless network.
Click Edit, and in the window that appears, select the IPv4 Settings or IPv6 Settings tab.
If the selected method is Automatic (DHCP), open the dropdown and select Automatic (DHCP) addresses only instead. If the method is set to something else, do not change it.
In the DNS servers field, enter the local DNS IP addresses, separated by a space: 192.168.1.254
Click Apply to save the changes.
If you are prompted for a password or confirmation, type the password or provide confirmation.
Test that your setup is working correctly;
Repeat the procedure for additional network connections you want to change.
What is specified by the host bits in an IP address?
The network part of an IP address indicates the network to which the host belongs.
The host bits or host part of an IP address points to the actual device that has an IP address on the network. It can be a computer, printer, router or any device with an IP address that has the same network part.
10BaseT is an Ethernet cabling standard. 10BaseT devices can transfer data at a rate of up to 10 Mbps, and use twisted pairs of wires in their Ethernet cabling, as opposed to a coaxial cable. If you see wiring with an RJ-45 plug on the end, you probably have a 10BaseT or backwards-compatible product (such as 100BaseT or 1000BaseT).
The media is used for showing out information to the world. The media can be used for advertising, informing and many others.
Why is it necessary to erase the startup configuration before reloading the router?
Erasing the startup configuration before reloading the router is necessary to ensure that the device starts with a clean slate, free from any previous configurations that may cause conflicts or issues. This is particularly important when troubleshooting problems or preparing a router for a new deployment. By doing so, the router will boot up with default settings, allowing for a fresh configuration process without unintended remnants of past settings.
What are the examples of serial and parallel ports?
give the difference between serial port and parallel port
Why does slope overload occur in delta modulation?
To reduce slope overload distortion ,the step size must be increased when the slope of the input signal is high.
The sawtooth is better able to
match the message in the regions of steep slope.
Which of the protocol is used for live video streaming?
To answer this question, one have to remind that on Internet, the HTTP protocol is dominant.
So, a good video streaming protocol must have the ability to use HTTP protocol.
We can quote:
- RTMP tunneled over HTTP (RTPMT)
- HTTP Live streaming (HLS)
What brand of network hub has the fastest transfer speed?
At a basic level, it's the next step in the Google Assistant, and it has the Assistant built in so you can use those voice commands while using the Hub. The Google Home Hub also has Chromecast and Bluetooth 5 built in, and is compatible with Android, iOS, Mac, Windows, and Chromebooks.
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How can define primary domain controller or additional domain controller?
On Windows Server Systems, a domain controller (DC) is a server that responds to security authentication requests (logging in, checking permissions, etc.) within the Windows Server domain. A domain is a concept introduced in Windows NT whereby a user may be granted access to a number of computer resources with the use of a single username and password combination.
Additional Domain Controller (ADC) or Backup Domain Controller (BDC) is a backup computer hosting DC services to be used as a backup in case your primary DC goes down or is somehow unavailable.
The Primary Domain Controller (PDC) and BDC synchronise their data on a regular basis so that either can be used as DC.
Has TC PIP replaced that protocol in the general usage or did another protocol replace it?
TCP/IP is the protocol used for the Internet. It will not be replaced anytime soon, it replaced a protocol called IPX/SPX which was used by Novell. But TCP/IP is here to stay.
What is the difference between a permanent address and a care of address?
A permanent address for a mobile node is it's IP address when it is at it's home network. A care-of-address is the one its gets when it is visiting a foreign network.
ODBS in computer stands for Open database connectivity. Whenever we are working on a project let it be java or php the to store the data in our project we need a database. For this this we need to create a database connection that is ODBC.
