EzDev.org

wireless interview questions

Top 15 wireless interview questions

1282 Jobs openings for wireless


"Starting Wireless Hotspot..." but nothing happens

I was trying to create an WiFi hotspot for my android device. I used ap-hotspot to do so.

I configured the ap-hotspot using

sudo ap-hotspot configure

Then I started ap-hotspot using

sudo ap-hotspot start

Then it shows this

Starting Wireless Hotspot...

And then nothing happens, no further message is displayed, hotspot is not created.

What is Wrong? How to fix it?


Source: (StackOverflow)

A tool to measure signal strength of wireless

I want to know if there exists any command line option or GUI tool (Ubuntu 11.10) so that I can measure the strength of wireless signal at a given location. I have a house where the wireless is not easily accessible at all corners I want to know at which corners or rooms the signal is weak.


Source: (StackOverflow)

How can I adjust the preferred WiFi order? [duplicate]

This question already has an answer here:

I am using 13.04 Ubuntu. I want to make order on multiple wireless access.

Is there any way to do this?


Source: (StackOverflow)

My WiFi adapter is not working at all, how to troubleshoot?

On this site I see hundreds if not a thousand questions being asked about issues with a Wireless LAN adapter not being detected/recognized by Ubuntu. Some mainstream adapters appear to be utterly broken in Linux support, while others just require some simple steps to get it to work.

The options to get it to work appear to be infinitely huge and I have no clue where to get started!

What is considered 'best practice'? What order of things to try is most efficient in terms of time, effort and imposes minimal risk to my Ubuntu installation? Please help me save time and guide me what to do, step by step.


Source: (StackOverflow)

Wifi doesn't work after suspend after 16.04 upgrade

This particular version of the "doesn't work after suspend" came after upgrading to 16.04. It seems that the upgrade includes a Wicd applet (added to Metacity Classic Gnome task bar alongside regular network icon), but doesn't seem to work after a suspend. A sudo service network-manager restart duplicates this problem. It takes a complete reboot to get Wifi going again. Any ideas why?


Source: (StackOverflow)

Share Wireless connection with Wired Ethernet Port

That's pretty much it. If I connect to the Internet on wlan0, how can I share this connection with a device plugged into my wired Ethernet port eth0?


Source: (StackOverflow)

Share wireless Internet connection through ethernet

I want to share the wireless Internet connection on my desktop with my old laptop, through ethernet.

I have ticked the option "Make available to others" on both connections, on my desktop, but my laptop doesn't connect. Am I doing something wrong or is it a bug?


Source: (StackOverflow)

connect to wifi from command line

Other posts seems to be addressing more complicated network connection issues from the command line.

The Unity panel Network indicator/button doesn't respond too well sometimes - it keeps trying to connect to a network even when i click on "disconnect", stuff like that.

So I want to go command line for the control. I don't like GUIs anyway.

Is there not some simple command line tool which can do something like the following?

wifi connect MyNetworkNameA
wifi disconnect
wifi connect MyNetworkNameB

Source: (StackOverflow)

How do I fix a "Wireless is disabled by hardware switch" error?

I just updated to Ubuntu 12.04 from 11.10 but soon after updating I was disappointed to see that

Wireless is disabled by hardware switch.

I can not click the button 'Enable wireless' which is greyed out. Without wireless my computer is useless as I have to connect by wire which is not practical. I have a Acer TravelMate 4500


Source: (StackOverflow)

How do I create a WiFi hotspot sharing wireless internet connection (single adapter)?

I know how to create a hotspot when connected to a wired network, but when I am using internet from a WiFi connection, this disconnects the wireless connection the moment I activate the hotspot.

In Windows I can use Connectify Hotspot, which enables me to share the internet connection from the same wireless adapter as I am creating an access point on. As you can read on the technology overview page:

Access Point mode allows you to create a hotspot using the same Wi-Fi card that you are using to access the Internet.

How do I do this on Ubuntu?


Source: (StackOverflow)

My wireless/WiFi connection does not work. What information is needed to diagnose the issue?

Your situation

  • You have successfully installed Ubuntu.
  • You have just downloaded and booted Ubuntu live media.

    The latest LTS (see also HWE) or latest non-LTS release are preferred. See the list of Ubuntu releases that are currently supported.)

  • You upgraded your Ubuntu installation to the latest release that the software updater offered you. WiFi worked before, but not now on the new release.

  • You migrated your existing Ubuntu installation to new hardware.

Your problem

  • The wireless of your laptop or dekstop is not working. You tried switching the wireless switch off and on and you tried rebooting several times, but you don't see any WiFi access points.
  • You can see your wireless access point, but you cannot establish a connection.
  • You want to analyze the problem, but you don't know where to start or what information you can provide.

This question and answer was written to give people the wireless script that will provide the information needed in most cases to diagnose their wireless issue's.

Related questions


Source: (StackOverflow)

How to setup an Access Point mode Wi-Fi Hotspot?

How to setup an Access Point mode Wi-Fi Hotspot?

Point to be noted: Wireless hotspots aren't the same as ad hoc networks. There is significant difference between the two. In short, ad hoc networks aren't supported on newer devices and most Android, Windows Phone and Blackberry devices (and maybe iOS devices too) whereas AP mode Wi-Fi hotspots are. To get an idea about AP mode hotspots, ad hoc networks and their difference, refer to this Wikipedia page and this article on Connectify website.


Source: (StackOverflow)

Installing Broadcom Wireless Drivers

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.

What are the steps to install Broadcom wireless drivers for a BCM43xx card?

I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.


lspci -vnn | grep Network showed:

Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b] 

iwconfig showed:

lo        no wireless extensions.
eth0      no wireless extensions.

NOTE: Answer below is updated every time new information is added and confirmed working.


Source: (StackOverflow)

How to connect and disconnect to a network manually in terminal?

Since the network manager is troubling me so much I want to replace it (possibly wicd orNM from ppa:volanin).

I do not know how to connect and disconnect to the network through the terminal without using network manager.

I would like a command-line way of managing the network.


Source: (StackOverflow)

Wireless networking not working after resume in Ubuntu 14.04

[Update]:
The same problem exists in Kubuntu and is solved in the same manner.
[Solved]:
By applying the following command nmcli nm I got the following:

Before suspend

RUNNING         STATE           WIFI-HARDWARE   WIFI       WWAN-HARDWARE   WWAN      
running         connected       enabled         enabled    enabled         enabled  

as can you see the state is connected and the rest are enabled and running

After suspend

RUNNING         STATE           WIFI-HARDWARE   WIFI       WWAN-HARDWARE   WWAN      
running         asleep          enabled         enabled    enabled         disabled

as can you see the state is asleep meaning our dear network manager is still napping, so to solve use the fallowing command line:
sudo nmcli nm sleep false
this tells the network manager to wake the hell up. to make this permenant :
create a script in /etc/pm/sleep.d containg the following (and don't forget to mark the script as executable):

#!/bin/sh

case "${1}" in
        resume|thaw)
        nmcli nm sleep false
                ;;
esac

Thanks to this

The original problem:

I just downloaded Ubuntu 14.04 and installed on my laptop: ASUS X61SL with Intel P8400 Core2Duo x64 processor.
When I close the lid, the system is suspended, but when I open the lid again and resume, the wireless networking is not activited (networking as a whole is disabled), and when I select "Enable Networking" nothing happens.
This is the information about my wireless adapter:

$ lspci | grep -i wireless
02:00.0 Network controller: Qualcomm Atheros AR928X Wireless Network Adapter (PCI-Express) (rev 01)  

This problem wasn't present in Ubuntu 13.04, Linux Mint Debian Edition or Debian 7 wheezy (GNOME or KDE).

Edit: few test with the following results :
The problem effects my wireless and wired networking.
Note: I need to add the pci=nomsi line to grub in order to boot.
When logging out manually then suspend then resume then log in every thing works just fine.
When suspending directly while logged in the problem happens.
Locking and suspending causes the same problem as suspending directly.
Also this problem appearnlty affects log out function: if you chose log out from the user menu in unity panel then you wan't log out, but if you use the command line gnome-session-quit --logout then you can log out.
Now with lshw -C network output:
Normal (fully functional networking):

  *-network               
       description: Ethernet interface
       product: 191 Gigabit Ethernet Adapter
       vendor: Silicon Integrated Systems [SiS]
       physical id: 4
       bus info: pci@0000:00:04.0
       logical name: eth0
       version: 02
       serial: 00:24:8c:1e:f8:53
       size: 10Mbit/s
       capacity: 100Mbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=sis190 driverversion=1.4 duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:19 memory:fddfcc00-fddfcc7f ioport:cc00(size=128)
  *-network
       description: Wireless interface
       product: AR928X Wireless Network Adapter (PCI-Express)
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlan0
       version: 01
       serial: 00:15:af:e2:13:db
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=3.13.0-24-generic firmware=N/A ip=6.6.6.8 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn
       resources: irq:16 memory:fdff0000-fdffffff

After resume ("/etc/pm/config.d" does not contains "unload_modules"):

 *-network DISABLED      
       description: Ethernet interface
       product: 191 Gigabit Ethernet Adapter
       vendor: Silicon Integrated Systems [SiS]
       physical id: 4
       bus info: pci@0000:00:04.0
       logical name: eth0
       version: 02
       serial: 00:24:8c:1e:f8:53
       size: 10Mbit/s
       capacity: 100Mbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=sis190 driverversion=1.4 duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:19 memory:fddfcc00-fddfcc7f ioport:cc00(size=128)
  *-network DISABLED
       description: Wireless interface
       product: AR928X Wireless Network Adapter (PCI-Express)
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlan0
       version: 01
       serial: 00:15:af:e2:13:db
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=3.13.0-24-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11bgn
       resources: irq:16 memory:fdff0000-fdffffff

When I added the file unload_modules to directory "/etc/pm/config.d" as suggested by here, after logging out, suspend ,resume then log in the networking works but I cannot connect to my wireless network.
Again the result of lshw -C network After resume ( "/etc/pm/config.d" contains "unload_modules"):

 *-network DISABLED      
       description: Ethernet interface
       product: 191 Gigabit Ethernet Adapter
       vendor: Silicon Integrated Systems [SiS]
       physical id: 4
       bus info: pci@0000:00:04.0
       logical name: eth0
       version: 02
       serial: 00:24:8c:1e:f8:53
       size: 10Mbit/s
       capacity: 100Mbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=sis190 driverversion=1.4 duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:19 memory:fddfcc00-fddfcc7f ioport:cc00(size=128)
  *-network DISABLED
       description: Wireless interface
       product: AR928X Wireless Network Adapter (PCI-Express)
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlan0
       version: 01
       serial: 00:15:af:e2:13:db
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=3.13.0-24-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11bgn
       resources: irq:16 memory:fdff0000-fdffffff

The contents of 'unload_modules" where:

SUSPEND_MODULES="$SUSPEND_MODULES ath9k"
SUSPEND_MODULES="$SUSPEND_MODULES sis190"

Where 'ath9k' is my wireless module and 'sis190' is my Ethernet module.


Source: (StackOverflow)