View Full Version : [ubuntu] Cannot connect to Wireless LAN in Ad-Hoc mode

March 12th, 2009, 02:17 AM
First, I have WindowsXP-based desktop with TP-Link TL-WN821N Wi-Fi card, mode set to Ad-Hoc. Security mode is None/Unencrypted. I use ICS on that interface, so DHCP is working there.
Second, I have HP 6830s laptop with Ubuntu 8.10 x64 and Intel 5100 Wi-Fi card, mode set to Ad-Hoc too. Driver is iwlagn, and I suppose it works fine. SSIDs on both machines are same.

The problem is, I cannot connect from Ubuntu laptop to Windows PC. Network Manager was useless, so I switched to WICD. It hangs during "Obtaining IP address" stage. I tried to follow these instructions: http://ubuntuforums.org/showthread.php?t=571188
I got same results in manual mode: upon executing dhclient wlan0 I have no DHCPOFFER reply from PC, and PC shows "no link" status as well.

However, I was able to connect using Windows 7 x64 (beta) on this laptop. Didn't enter anything, just made a single click. More interesting, I'm able to connect from Windows PC to Ubuntu laptop. I press "connect" in Windows and in the same time execute dhclient wlan0 on Ubuntu. Windows connects and Ubuntu receives DHCP settings. Everything works but WICD behaves oddly: about 10 seconds it shows "Connected to my_ssid at 0% (", then about 3 seconds it shows "Not connected", and round and round.

So how can I connect from Ubuntu?

Oh, BTW here's ls-es:

Bus 001 Device 002: ID 03f0:171d Hewlett-Packard Wireless (Bluetooth + WLAN) Interface [Integrated Module]

03:00.0 Network controller: Intel Corporation Wireless WiFi Link 5100
86:00.0 Ethernet controller: Marvell Technology Group Ltd. Device 436c

lshw -C network
description: Wireless interface
product: Wireless WiFi Link 5100
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: wmaster0
version: 00
serial: 00:21:6b:1f:c0:70
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list logical ethernet physical wireless
configuration: broadcast=yes driver=iwlagn latency=0 module=iwlagn multicast=yes wireless=IEEE 802.11abg
description: Ethernet interface
product: Marvell Technology Group Ltd.
vendor: Marvell Technology Group Ltd.
physical id: 0
bus info: pci@0000:86:00.0
logical name: eth0
version: 00
serial: 00:22:64:5b:f0:6e
size: 1GB/s
capacity: 1GB/s
width: 64 bits
clock: 33MHz
capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=sky2 driverversion=1.22 duplex=full firmware=N/A ip= latency=0 link=yes module=sky2 multicast=yes port=twisted pair speed=1GB/s
description: Ethernet interface
physical id: 2
logical name: pan0
serial: 1e:3c:a7:6a:fd:61
capabilities: ethernet physical
configuration: broadcast=yes driver=bridge driverversion=2.3 firmware=N/A link=yes multicast=yes

March 12th, 2009, 02:59 AM
Just tried Network Manager again. Same thing: I can only connect from Windows to Ubuntu. Network Manager also shows 0% signal quality while it's 96-100% in real.