View Full Version : [ubuntu] Wireless interface disconnected, anyone know how to reconnect?

December 18th, 2010, 06:20 PM

I'm using the following wireless card:

description: Wireless interface
product: RTL8187SE Wireless LAN Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:02:00.0
logical name: wlan0
version: 22
serial: 00:24:21:4e:e6:27
width: 32 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=r8180 latency=0 multicast=yes promiscuous=yes wireless=802.11b/g
resources: irq:17 ioport:b000(size=256) memory:dfc00000-dfc03fff

it was working previously and is still recognised with both ifconfig and iwconfig and I can bring it up and down etc.

however I can't scan for wireless networks and have problems using applications such as kismet so I ran nm-tool and this was my output:

- Device: wlan0 ----------------------------------------------------------------
Type: 802.11 WiFi
Driver: r8180
State: disconnected
Default: no

does anyone know how I am able to reconnect it?

December 18th, 2010, 06:41 PM
promiscuous=yesI wonder what that means. When you do:
sudo ifconfig wlan0 down
sudo iwconfig wlan0 mode managed
sudo ifconfig wlan0 upIs the behavior improved?

December 18th, 2010, 07:28 PM
no there is no change in behaviour, infact under iwconfig before and after running the commands the mode specified was managed, so not sure why it's listed as promiscuous somewhere else....this was my output

wlan0 802.11b/g Mode:Managed Frequency=2.462 GHz
Access Point: Not-Associated Bit Rate:11 Mb/s
Retry:on RTS thr:off Fragment thr:off
Power Management:off
Link Quality=0/100 Signal level=0 dBm Noise level=0 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

You have any idea what could be causing this?

December 18th, 2010, 07:33 PM
I wonder what that means. When you do:
sudo ifconfig wlan0 down
sudo iwconfig wlan0 mode managed
sudo ifconfig wlan0 upIs the behavior improved?


Found this old thread

Saying "
My understanding, is that when a networking device is in promiscuous mode (ifconfig device promisc), it should receive all packets whether the packet is directed to that device or not. With wired networking, the router/switch needs to be able to replicate all traffic to a single specified port (or if you're using a standard hub, since all traffic is indiscriminately anyway).

With wireless devices, since all the packets are broadcast anyway, a wireless device in promiscuous mode should pick up all wireless traffic on that SSID and channel, regardless of the target destination.

Don't really understand the explanation though!

December 18th, 2010, 07:56 PM
Ye that just seems to be an explanation of what promiscuous mode is, due to my work I often use it, however when I try to run something such as kismet which uses the card in promiscuous mode it wont start claiming problems with the interface.

I think the problem is due to it being listed as disconnected in nm-tools however i'm not sure how I can reconnect it...also when I run ifdown I get the following:

ifdown: interface wlan0 not configured