lan interview questions

Top lan frequently asked interview questions

My colleague often shuts down my machine through the LAN - how do I prevent it?

This might sound weird. My colleague and I were working on a Windows machine. He frequently shuts it down through the LAN.

He usually follows these steps:

  1. Access command prompt, enter shutdown -i.
  2. Choose my IP address, click on Shutdown.
  3. Select a timeout of 2–3 seconds.
  4. Click OK

Unfortunately, I cannot disable remote access to my computer. Is there a way to prevent this?

Source: (StackOverflow)

How to use Wireless and Wired Connection both at a same time in Windows 7?

I am using Windows 7. Problem is while using internet in Wireless if i connect LAN cable to my laptop, it stop Wireless connection and Wired Connection gets active.

I am using Internet using Wireless and doing my work through Wired Connection. I want to use Wireless and Wired Connections both at same time

HOW to use wireless and wired connection at the same time?

Source: (StackOverflow)

How do I change the Windows7 LAN proxy config from the command line?

In Windows 7, Is it possible to define/change the proxy config from the command line?

So, using the GUI, I would go:

Start → Control Panel → Network and Internet → Internet Options → Connections → LAN Settings

and then

  • enable/disable the proxy;
  • define IP:port of proxy server.

But I would like to rather do this from the command line (so that I can run the command from a batch-file with a shortcut key — enabling me to switch proxy configs using a short-cut, rather than having to wade through the MS wizard).

I've looked at using netsh.exe to change the settings for WinHTTP, but this seems to be thr wrong thing to do, as the WinHTTP setting do not appear to be related to the LAN settings.

Source: (StackOverflow)

How do IP answer packets reach their destination inside of a private LAN?

This is a little theory question that has been confusing me for a pretty long time.

Basically, if we are inside of a private LAN, and we want incoming packets to reach, for example, an HTTP server located on one of the machines, we forward ports so that incoming packets reach exactly that computer.

Now, I'm quite confused as to how 'response' packets reach their destination inside of a LAN, like, when we open a web page or so. Can't really find any useful information on that topic.

I hope someone can give me a couple of clues or link me to some information that might explain it. Thanks.

EDIT: I think I should clarify. An example of what I'm asking would be something like this:
1. A computer inside of a LAN with a single external IP tries to load a web-page from a web-server outside of this LAN (Basically on the Internet)
2. The web-server responds and sends the web-page back to that computer.

What quite confuses me at this point is, how does the router know what computer to send the incoming data (given the router is connected to a LAN with multiple computers) without previous port forwarding.

Source: (StackOverflow)

How can I join two simple home networks together using an ethernet cable?

I want to join two different home networks together like so:

PC A1      PC A2                              PC B1      PC B2
  \         /                                   \         /
   Gateway A      <----- ethr. cable ----->      Gateway B
       |                                             |
  ADSL modem A                                  ADSL modem B

Both networks are of the basic residential type with identical configuration, with all PCs running Vista/7. The point is to temporarily join two apartments in a building for gaming and file sharing, and the holy grail would be:

  1. PCs on network A can access PCs on network B and vice-versa (file shares and gaming).
  2. Each network uses its own internet connection.
  3. Data between networks shouldn't take a trip through the internet (broadband upload speeds are severely capped)
  4. A network's internet access should continue working if the joining cable is disconnected with minimal configuration changes.

How closely can this be achieved?

Source: (StackOverflow)

Best way to transfer files over a LAN between two Linux computers

I want to transfer files (a music folder) between two Linux computers. After searching for the best way to do this, I've seen that there are lots of ways of doing this. I know this has been asked a lot, everywhere and all the time. The main problem with this is that there is no clear, recent consensus on one best way to do this task in 2011 for Linux beginners (even depending on some parameters).

So in the spirit of the Stack Exchange websites, I want this not to be related to my particular situation, but more of a guide to others as well on how to transfer files between two Linux computers over a local network. I think a wiki would be useful for many.

Here's what I found so far:

  • ssh
  • sshfs
  • scp
  • sftp
  • nfs
  • samba
  • giver

What is the easiest? Most flexible? Simplest? Best solution? What are the pros and cons of each? Are there other (better) options? What are the parameters in choosing the best method (solution might depend on number of files, filesize, easiness vs. flexibility, ...)?

Source: (StackOverflow)

Set Ethernet Network as Metered Connection in Windows 8

Windows 8 introduced a new feature which allows users to set any Wi-Fi network as metered so that they can check their bandwidth usage:

[img credit]

But, it doesn't allow users to set any Ethernet network as metered:

So, is there a trick/workaround to do it?

Source: (StackOverflow)

What do different types of LAN IP addresses mean?

I have seen LAN IP addresses in the following ways:





127.0.0.* (This one is normally with a 1, and I'm not sure if it is LAN, since I see it normally with proxy stuff.)

So, why are there different forms of an LAN IP addresses, and what do they mean/represent?

Source: (StackOverflow)

How can I force Windows 7 to give my LAN (wired) conection priority over my WiFi?

Given the choice between my LAN (wired) and my WiFi connections, my Windows 7 PC gives priority to the WiFi - how can I make it prioritize the LAN connection?

Source: (StackOverflow)

Test the Speed of a Local Area Network

How can I test the speed of a LAN? I hope there is something baked into Windows to do this, because I am unable to install any third-party products.

Source: (StackOverflow)

Dropbox alternative with local sync support? [closed]

I am currently using Dropbox. Just decided to sync my huge (about 5 GB) iTunes Library (music collection) in Dropbox. For that I must subscribe to their paid account. But before I do so, I'd like evaluate the alternatives.

Is there an alternative that does this?

  • Local LAN sync (eg: sync my huge music collection across computers in local network without uploading/downloading them to internet)

The following would be nice (but not required):

  • Native android client - so music will be made available in the Android music app / SDHC card
  • Selective sync: sync particular folders / exclude certain folders on certain computers .. eg: excluding porn folder on work computers ;-)

Just like Dropbox, it MUST work on 64-bit Windows, Linux and Mac.

Know of any? (I am currently evaluating Spideroak. Boy, was it so complicated to use?)

Source: (StackOverflow)

What's wrong with my custom LAN cable?

This question is basically a continuation of this previous question. Never mind, here's the deal:

I've made a LAN cable that goes through a wall, but it doesn't work. The cable is roughly 10m/30ft long. I crimped both ends myself according to this detailed explanation, and the job looks to be well done; all the wires are all the way in the plug.
I bought a cable tester after not being able to fix this. I thought perhaps the cable this is what I bought has a bad kink somewhere. But the cable tester says all wires are okay! The cable tester flashes its lights nicely in the correct sequence. According to the half-chinese instruction page, this indicates that everything is wired correctly. Even if I might have the wrong color sequence, the copper itself seems to be correct.

But when I unplug the LAN cable sneaking through the hallways, and connect this new LAN cable instead, Windows reports that there's no network.

What can be wrong? How can I find out?

Updated: Italic text above, in response to the first few answers.

Source: (StackOverflow)

How do I connect two computers with a LAN cable?

I have two machines - Windows XP and a laptop using Windows 7. I connected them with a WLAN cable.

On the Windows XP machine, I set the IP address to On the Windows 7 laptop, I set the IP address to

The laptop can see the Windows XP machine, but Windows XP machine cannot see the Windows 7 machine. But this does NOT concern me. I want to move the files from my desktop (Windows XP) to Windows 7 (laptop). That's why I'm going through all this.

The problem is that when I try to connect from Windows 7 to Windows XP machine, I get this window:

alt text

I don't understand what username/password is needed. I use none on the Windows XP machine. I tried all usernames - no success.

Please explain in deep details how to solve my problem so I can connect to my Windows XP machine.

EDIT: Maybe this can help: the Windows XP machine is named 'I' and 'Проданов III' is the name of the laptop. Both computers share one workgroup - WORKGROUP.

Source: (StackOverflow)

How can I make these computers share folders again?

OK, I've had enough of this.

My mom's family's business is having problems with their two computers, which we'll call PC1 and PC2. Both are running Windows 7, and they used to have some shared folders. But for maybe the past couple of weeks, they're not sure how long, that hasn't been working. PC2 was able to see PC1 (it showed up under "Network"), but not access any files in there. (Folders, yes; either it could see those or it remembered them.) PC1 couldn't see PC2 at all.

After fiddling with a whole bunch of junk and rebooting PC2, I managed to make it show up on PC1. But when I click on "PC2," it says "Windows cannot access \PC2." Pinging PC2's IP address (at least the one that showed up under "IPv4 Address" when I ran ipconfig on PC2) turned up nothing -- request timed out.

The name of the network is the same in Network and Sharing Center on both computers, as are the type and the workgroup name under System (the latter being the thing I changed on PC2 before rebooting). It's a little inconsistent on whether "PC1" is capitalized as such or as "pc1." The router's a 2Wire 1701HG Gateway. Aside from that, I don't know what to look for -- if it's a firewall issue or what. LANs aren't exactly my field of expertise.

EDIT: Forgot to mention -- both computers have Internet access.

Source: (StackOverflow)

Getting the local IP address in Ubuntu 10.04 LTS

I am trying to get my locally assigned IP address from Ubuntu 10.04 LTS with ifconfig and what I'm getting is my external IP address (in other words, it's the same IP I see on

When running ifconfig eth0, inet addr shows my external IP address instead of the local address.

How do I get my local IP address ?

Source: (StackOverflow)