Intel WiFi Link 5100 AGN cannot connect to N networks in Ubuntu

[Schadenfroh]

Greetings, having a really frustrating problem since I upgraded to a new router that supports Wireless N.

Hardware
Intel Wifi Link 5100
http://www.intel.com/Assets/PDF/prodbrief/319981.pdf

Router: Asus RT-n16
Tested with both Tomato USB (Teddy Bear) and currently using DD-WRT Big build 14929 (latest recommended build for this router), set to N only.


Software
Operating System: Ubuntu 10.10 x64 (fresh install)
uname -a:

Linux SchadenBook 2.6.35-27-generic #48-Ubuntu SMP Tue Feb 22 20:25:46 UTC 2011 x86_64 GNU/Linux

lshw -C network

*-network
description: Wireless interface
product: PRO/Wireless 5100 AGN [Shiloh] Network Connection
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlan0
version: 00
serial: 00:22:fa:c3:d7:7c
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlagn driverversion=2.6.35-27-generic firmware=8.24.2.12 latency=0 link=no multicast=yes wireless=IEEE 802.11abg
resources: irq:47 memory:f4200000-f4201fff

iwconfig:

lo no wireless extensions.

eth0 no wireless extensions.

wlan0 IEEE 802.11abg ESSID:"SchadenNet"
Mode:Managed Frequency:2.437 GHz Access Point: Not-Associated
Tx-Power=15 dBm
Retry long limit:7 RTS thrff Fragment thrff
Power Managementff

ifconfig:

wlan0 Link encap:Ethernet HWaddr 00:22:fa:c3:d7:7c
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)

dmesg:

12.451551] iwlagn: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree:
[ 12.451553] iwlagn: Copyright(c) 2003-2010 Intel Corporation
[ 12.451641] iwlagn 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
[ 12.451670] iwlagn 0000:03:00.0: setting latency timer to 64
[ 12.451772] iwlagn 0000:03:00.0: Detected Intel(R) WiFi Link 5100 AGN, REV=0x54
[ 12.475313] iwlagn 0000:03:00.0: Tunable channels: 13 802.11bg, 24 802.11a channels
[ 12.475453] iwlagn 0000:03:00.0: irq 47 for MSI/MSI-X
[ 12.519466] iwlagn 0000:03:00.0: loaded firmware version 8.24.2.12
[ 12.526599] phy0: Selected rate control algorithm 'iwl-agn-rs'

ls -l /lib/firmware | grep iwl:

-rw-r--r-- 1 root root 335056 2010-12-13 15:01 iwlwifi-1000-3.ucode
-rw-r--r-- 1 root root 150100 2010-12-13 15:01 iwlwifi-3945-2.ucode
-rw-r--r-- 1 root root 187972 2010-12-13 15:01 iwlwifi-4965-2.ucode
-rw-r--r-- 1 root root 345008 2010-12-13 15:01 iwlwifi-5000-1.ucode
-rw-r--r-- 1 root root 353240 2010-12-13 15:01 iwlwifi-5000-2.ucode
-rw-r--r-- 1 root root 337400 2010-12-13 15:01 iwlwifi-5150-2.ucode
-rw-r--r-- 1 root root 454608 2010-12-13 15:01 iwlwifi-6000-4.ucode
-rw-r--r-- 1 root root 444128 2011-02-11 09:20 iwlwifi-6000g2a-5.ucode
-rw-r--r-- 1 root root 460912 2011-02-11 09:20 iwlwifi-6000g2b-5.ucode
-rw-r--r-- 1 root root 463692 2011-02-11 09:17 iwlwifi-6050-4.ucode
-rw-r--r-- 1 root root 469780 2010-12-14 11:18 iwlwifi-6050-5.ucode

I know the hardware and router are both fine as I dual boot with Windows 7 x64 and it connects perfectly to my N network under Windows.

I can connect to it just fine using 802.11 G in Ubuntu 10.10 x64, but it refuses to connect using N and just keeps trying.

I suspect that the driver for Ubuntu 10.10 does not support wireless N, although I do not know how to resolve this if this is the case.

I am not familiar with loading drivers in Linux. I tried, per the Intel readme file, copying the latest driver from http://www.intellinuxwireless.org/ into /lib/firmware and restarting, but I think there is likely more to it than that as it did not resolve it, so I removed it.

Any thoughts on how to correct this or if I should report it as a bug?

Thanks

 

[Schadenfroh]

scarey9 over at the Ubuntu forums found a fix.

sudo vim /etc/modprobe.d/intel-5300-iwlagn-disable11n.conf

Change:
options iwlagn 11n_disable=1

To:
options iwlagn 11n_disable=0