wlan0 No scan results

[someguydude]

Hey List!

I have loaded Ubuntu 12.04 server 32 bit.

did not configure wlan0 during setup ... selected eth0 as primary access ( I wanted things clean to test).

iwconfig shows wlan0 no problems.
light is off on wifi NIC.
I do:
ifconfig wlan0 up
and then light comes on and I see it in ifconfig where before it wasnt.

no problems so far.

then:
iwlist wlan0 scan

gives no results (there are dozens of wifi in my hood and my Droid shows my test AP next t this server).

What gives?

(the person who figures it out will win ...

... a smiley face).

Thanks

[rokytnji]

errr, that should be

sudo iwlist wlan0 scan

unless you just did not post the whole command maybe.

Just something I use for posting wireless info

sudo echo uname: && uname -a -m -p && echo lspci: && lspci && echo lsusb: && lsusb && echo lsmod: && lsmod && echo ifconfig: && ifconfig && echo ifconfig -a: && ifconfig -a && echo iwconfig: && iwconfig && echo resolv.conf: && cat /etc/resolv.conf && echo route: && route -n

also. do you have wireless-tools installed?

$ apt-cache policy wireless-tools
wireless-tools:
  Installed: 30~pre9-8
  Candidate: 30~pre9-8
  Version table:
 *** 30~pre9-8 0
        500 http://http.us.debian.org/debian/ testing/main i386 Packages
        100 /var/lib/dpkg/status

[someguydude]

uname:
Linux ubuntu 3.2.0-23-generic-pae #36-Ubuntu SMP Tue Apr 10 22:19:09 UTC 2012 i686 i686 i386 GNU/Linux
lspci:
00:00.0 Host bridge: Intel Corporation 82Q35 Express DRAM Controller (rev 02)
00:01.0 PCI bridge: Intel Corporation 82Q35 Express PCI Express Root Port (rev 02)
00:02.0 VGA compatible controller: Intel Corporation 82Q35 Express Integrated Graphics Controller (rev 02)
00:02.1 Display controller: Intel Corporation 82Q35 Express Integrated Graphics Controller (rev 02)
00:03.0 Communication controller: Intel Corporation 82Q35 Express MEI Controller (rev 02)
00:03.2 IDE interface: Intel Corporation 82Q35 Express PT IDER Controller (rev 02)
00:03.3 Serial controller: Intel Corporation 82Q35 Express Serial KT Controller (rev 02)
00:19.0 Ethernet controller: Intel Corporation 82566DM-2 Gigabit Network Connection (rev 02)
00:1a.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 02)
00:1a.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 02)
00:1a.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 02)
00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 02)
00:1d.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 02)
00:1d.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 02)
00:1d.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 02)
00:1d.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 92)
00:1f.0 ISA bridge: Intel Corporation 82801IO (ICH9DO) LPC Interface Controller (rev 02)
00:1f.2 IDE interface: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 4 port SATA Controller [IDE mode] (rev 02)
00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 02)
00:1f.5 IDE interface: Intel Corporation 82801I (ICH9 Family) 2 port SATA Controller [IDE mode] (rev 02)
lsusb:
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 003: ID 07d1:3c0a D-Link System DWA-140 RangeBooster N Adapter(rev.B2) [Ralink RT3072]
Bus 006 Device 002: ID 0451:2046 Texas Instruments, Inc. TUSB2046 Hub
Bus 006 Device 004: ID 06f2:007b Emine Technology Co.
lsmod:
Module                  Size  Used by
snd_hda_codec_analog    75395  1
arc4                   12473  2
ppdev                  12849  0
dcdbas                 14098  0
rt2800usb              22300  0
rt2800lib              53264  1 rt2800usb
crc_ccitt              12595  1 rt2800lib
rt2x00usb              20061  1 rt2800usb
rt2x00lib              48858  3 rt2800usb,rt2800lib,rt2x00usb
mac80211              436455  3 rt2800lib,rt2x00usb,rt2x00lib
psmouse                72846  0
serio_raw              13027  0
snd_hda_intel          32765  0
snd_hda_codec         109562  2 snd_hda_codec_analog,snd_hda_intel
snd_hwdep              13276  1 snd_hda_codec
usbhid                 41906  0
cfg80211              178679  2 rt2x00lib,mac80211
i915                  414603  1
snd_pcm                80845  2 snd_hda_intel,snd_hda_codec
drm_kms_helper         45466  1 i915
snd_timer              28931  1 snd_pcm
hid                    77367  1 usbhid
snd                    62064  6 snd_hda_codec_analog,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_timer
soundcore              14635  1 snd
drm                   197692  2 i915,drm_kms_helper
snd_page_alloc         14108  2 snd_hda_intel,snd_pcm
parport_pc             32114  1
mac_hid                13077  0
i2c_algo_bit           13199  1 i915
video                  19068  1 i915
mei                    36570  0
lp                     17455  0
parport                40930  3 ppdev,parport_pc,lp
e1000e                140005  0
ifconfig:
eth0      Link encap:Ethernet  HWaddr 00:1e:c9:7d:c4:36
          inet addr:192.168.168.201  Bcast:192.168.168.255  Mask:255.255.255.0
          inet6 addr: fe80::21e:c9ff:fe7d:c436/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2226 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2591 errors:0 dropped:0 overruns:0 carrier:0
          collisions:236 txqueuelen:1000
          RX bytes:189336 (189.3 KB)  TX bytes:537240 (537.2 KB)
          Interrupt:21 Memory:fe9e0000-fea00000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:24 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1888 (1.8 KB)  TX bytes:1888 (1.8 KB)

wlan0     Link encap:Ethernet  HWaddr fc:75:16:85:29:1b
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

ifconfig -a:
eth0      Link encap:Ethernet  HWaddr 00:1e:c9:7d:c4:36
          inet addr:192.168.168.201  Bcast:192.168.168.255  Mask:255.255.255.0
          inet6 addr: fe80::21e:c9ff:fe7d:c436/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2235 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2611 errors:0 dropped:0 overruns:0 carrier:0
          collisions:244 txqueuelen:1000
          RX bytes:189912 (189.9 KB)  TX bytes:540748 (540.7 KB)
          Interrupt:21 Memory:fe9e0000-fea00000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:24 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1888 (1.8 KB)  TX bytes:1888 (1.8 KB)

wlan0     Link encap:Ethernet  HWaddr fc:75:16:85:29:1b
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

iwconfig:
lo        no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:"mikienet24ghz"
          Mode:Managed  Frequency:2.462 GHz  Access Point: Not-Associated
          Tx-Power=20 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:on

eth0      no wireless extensions.

resolv.conf:
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
route:
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.168.0   0.0.0.0         255.255.255.0   U     0      0        0 eth0

Yes I used sudo (I left it out of the post ... shouldn't have)

Wireless tools are installed.

This Dell 755 optiplex runs with this 12.04 32 bit server and the wifi NIC many times before.
If I select the wlan0 as primary and enter wpa credentials I can get inet up during setup and install no problems.

Today I have reloaded it many times wifi perfect.

Only this last time I selected the eth0 as primary so I could test something.

[rokytnji]

Maybe this site will help in understanding what you need to do for wlan0 since your /etc/resolv.conf has it shown as left out.

Starting with

Dealing with our “links” – interfaces bringing them up and down

This is the easy way, for home networks with 1-2 box’s connected and this is the “plug’n play” way. First we bring the interfaces up :

#ip link set eth0 down ==> Same as ifconfig eth0 down
#ip link set wlan0 down ==> Same as ifconfig wlan0 down

Linux Network Configuration for home Users | Linux Networking how-to | AlbanianWizard

[someguydude]

That's a great link for network setup but it doesn't help me with my problem.

I use this box for experimentation so I reload it many times a day.

If I load ubuntu 12.04 server (32 bit) and select WLAN0 as primary ... everythiong works perfectly.
sudo iwlist wlan0 scan
yields results.

If I select eth0 during ubuntu install ... wlan0 says up and ok but simply does not work but everything says it is working ... light flashing on NIC etc ...

[Steven_G]

If I select the wlan0 as primary and enter wpa credentials I can get inet up during setup and install no problems.

Emphasis added / Off topic / A word to the wise...

I'm assuming you're probably not too concerned about security on this box if you're intentionally blowing it up / re-installing / experimenting several time a day.

But, you should seriously consider reconfiguring your router for better network security by turning WPA off in the router configuration if this is the same router that the rest of your network is on.

There is a HUGE hole in WPA. It's every bit as bad, if not worse than the hole in WEP.

There are now automated tools available that can crack WPA and allow full access to your network in an average time of about 10 minutes.

[someguydude]

Great Advice Steven however ...

I have a test router and it connects to nothing so I'm ok.
I need to try different encryptions to test, evauluate and learn on.

you see .... (sad violin music) ... I ... am a Windows guy ... and I must now repent my sins and get on with my IT career.

hence the lab environment.

I did think of one possibility as to the weird wireless problem I have.

When I select WLAN0 as primary and enter wpa creds I get to the net during setup and the latest patches are applied where when I select eth0 (no net) there is no way for Ubuntu setup to do this.

This has to be my problem.

how can I manually get the latest patches on CDROM?

[rokytnji]

how can I manually get the latest patches on CDROM?

In AntiX that I run. We use a snapshot script for remastering a live iso run to include any custom tweaks we may wish to use. In Ubuntu. I guess you need to look into using remastersys

I was under the impression that this was a server permanent install and that you just needed to bring up wlan0 after initial install. Not a live cd run. Because you keep saying

during ubuntu install

instead of "live cd run".

[Steven_G]

OK, I haven't really started playing with servers yet. But, AFAIK, they're usually headless(?) and remastersys requires a DE/GUI. It may work in command line? (But right now that would be beyond my skill level.) However, since you're a doze guy I figure you're probably familiar with PXE?

In poking around I've seen some stuff saying that there is now a PXE for Ubuntu.

I *think* that you would need to build a custom PXE and slipstream the patches in to it to create a fully up to date Live CD to play with. If you're not going to put it on metal then you'll probably have to load the PXE in to a work environment every so often and add the latest batch of patches.

[someguydude]

I swapped out the wireless usb NIC in question (DWA-140 DLINK) with another vendor. Choosing ETH0 as primary NIC during Ubuntu server install, WLAN0 works fine so I have to conclude that:

> if you install Ubuntu 12.04 server (32 bit) on a dell 755 with a DLINK DWA-140 B2 and select WLAN0 as your primary NIC then put in your WPA ESSID and pass phrase it connects to the net during install and patches itsels and works fine after many many many warm, cold, and tepid reboots with no problems.

However ...
> if you select ETH0 ... and that NIC does not route to the internet ... then your DLINK DWA-140 B2 will seem to work and the light will flash and yet it will not work at all ... for you are Damned ... and lost forever.

Issue resolved.
I win the smilly face