[solved] 4 USB Wifi Adaptors that work out of the box in Arch

stevepa · 2012-07-08 02:17:35

I wanted to share my experience with four different USB WIFI adaptors, that I am using in Arch Linux on a laptop.

See my other threads, but what drove this testing, was the sudden failure of my TP-Link adaptor, TL-WN821N, in a longstanding and fully updated installation. This testing was done in a recent installation.

The software/network variables I tested were:
1. The current production Kernel: linux-3.4.4-2 w/ Broadcom B43 module blacklisted
2. The LTS kernel: 3.0.36-1 w/ Broadcom B43 module blacklisted
3. WPA2 connection at home
4. Open Connection at Starbucks

If it matters, I am running XFCE, WICD, DHCP, dhcpcd. rc.conf is vanilla, with dbus and wicd starting in the DAEMONS line as per the wiki. No other module config done except the blacklist. As the kernel directly supports these devices, I did not install any other drivers.

The WIFI devices are:
1. Trendnet TEW-424UB - http://www.amazon.com/TRENDnet-54Mbps-W … +TEW-424UB
lsusb: 8189 Realtek Semiconductor Corp. RTL8187B Wireless 802.11g 54Mbps Network Adapter

2. TP-Link TL-WN821N - http://www.amazon.com/gp/product/B002T4 … 01_s00_i00
lsusb: 7015 Atheros Communications, Inc. TP-Link TL-WN821N v3 802.11n [Atheros AR7010+AR9287]

3. TP-Link TL-WN722N - http://www.amazon.com/gp/product/B002WB … 06_s00_i00
lsusb: 9271 Atheros Communications, Inc. AR9271 802.11n

4. Panda Mini Wifi (b/g/n) 150Mbps Wireless-N 2.4GHz USB Adapter - http://www.amazon.com/Panda-150Mbps-Wir … =de_a_smtd
lsusb: 3070 Ralink Technology, Corp. RT2870/RT3070 Wireless Adapter

I first tested at home against my WPA connection with all kernels and devices. Result: all devices associated, and acquired IP without issue. I tested each by just unplugging one and plugging another, all without rebooting. I just went into the wicd network manager dialog and activated the connection.

When I went to Starbucks to test the open wifi connection, things were not as nice.

1. Current kernel, open wifi, testing the Trendnet and the two TP-Links--> device associates but FAILS to get/assign IP.
2. Current kernel, open wifi, testing the Panda Mini wifi--> device associates and gets IP.
3. LTS kernel, open wifi, testing all devices--> associates and gets IP.

My preliminary findings suggest that the Panda is the only device of the four that can make a connection in every scenario. Of course YMMV. I will do some more testing. For the LTS kernel, I can recommend each of these devices.

Hope this helps someone.
Steve.

Update 11 November 2012
At this point, on my 64 bit system fully updated, on systemd, running kernel 3.6.6-1-ARCH #1 SMP PREEMPT Mon Nov 5 11:57:22.

Retesting at (Starbucks, essid=attwifi):
1. Current kernel, open wifi, testing the Trendnet and the two TP-Links--> device associates and gets IP w/script below.
2. Current kernel, open wifi, testing the Panda Mini wifi--> device associates and gets IP w/script below.
3. NOT TESTED FOR THE UPDATE--->LTS kernel, open wifi, testing all devices--> associates and gets IP.

My understanding at this point can be summarized as follows:
1. Read the wiki section on manually setting up wifi. Do not be tempted to install the automatic tools yet, like wicd or netcfg.
2. Get your open and encrypted connections working first with the manual tools, like iwconfig, ip link, wpa_supplicant.
3. Subject to confirmation, I believe that the "-t 0" parameters to dhcpcd has eliminated constant disconnects. (Before I added the "-t 0" parm, I discovered that the connection would lose the IP so dhcpcd would constantly reacquire another one. Internet connections would appear to work, but in a very broken manner.)
4. Strongly consider using only scripts as below to manage your wifi connections. This is very easy.

The script FWIW that documents how I start the open wifi connection at attwifi points:

#! /bin/bash
#
#connects the interface wlan0 to ATT Wifi hotspots
#
echo bringing wlan0 up
ip link set wlan0 up
sleep 2
echo setting essid attwifi
iwconfig wlan0 essid attwifi
sleep 2
echo getting ip
dhcpcd -t 0 wlan0
echo done

Update Mid May 2013: The two TP-Links fail on waiting on carrier. I consider them out of action on Arch Linux. The Panda works as it always did.

Last edited by stevepa (2013-05-27 05:24:11)

.:B:. · 2012-07-08 11:54:11

It's nice you want to share your experience, but what would really help people is mentioning the chips all those devices are using. Their marketing names are just marketing names, it doesn't tell you anything about the hardware inside, and that's what matters.

Chip name, and lspci output.

As for your Starbucks test case, I am not sure just your not getting an IP would mark those adaptors as 'problematic'. We cannot assess how thorough your Linux networking knowledge is (maybe by reading those other threads, but you created a separate thread, so...), and you don't really say more besides that it didn't work, so it's a pretty generic problem, and generic problems can have tons of solutions. Even simple, obvious ones that you overlook because you're so caught up in it (happens to the best and brightest).

Last edited by .:B:. (2012-07-08 11:58:21)

stevepa · 2012-07-08 16:10:01

.:B:. wrote:

It's nice you want to share your experience, but what would really help people is mentioning the chips all those devices are using. Their marketing names are just marketing names, it doesn't tell you anything about the hardware inside, and that's what matters.
Chip name, and lspci output.
As for your Starbucks test case, I am not sure just your not getting an IP would mark those adaptors as 'problematic'. We cannot assess how thorough your Linux networking knowledge is (maybe by reading those other threads, but you created a separate thread, so...), and you don't really say more besides that it didn't work, so it's a pretty generic problem, and generic problems can have tons of solutions. Even simple, obvious ones that you overlook because you're so caught up in it (happens to the best and brightest).

Thanks for the reply.

I will add chipset names as I have time, but a temporary workaround is...google!

You mentioned lspci. I think a better choice would be lsusb as my devices were all USB.

I offer this short info to others as what I used:

Beginners Guide: https://wiki.archlinux.org/index.php/Beginners'_Guide
Wireless setup: https://wiki.archlinux.org/index.php/Wireless_Setup
Wicd: https://wiki.archlinux.org/index.php/Wireless_Setup
And other info on DHCP and its friend dhcpcd, ip, iwconfig, ifconfig (I know it is old), dhcpcd. And config files rc.conf, modprobe.blacklist=stuff

In my research, I found "tons" of forum posts, but few or none were real solutions, except: Use the LTS kernel (mentioned as a workaround on the web at least for Atheros chipset devices though I thought the current kernel had that issue fixed).

In general, I think for me and many based on number of forum posts, getting wifi to work is a challenge. A challenge even for devices that have been around for years, and in the the kernel for a long time also.

If this info is useless, then the moderators can delete it. :-)

Regards
Steve.

Last edited by stevepa (2012-07-08 18:00:50)

.:B:. · 2012-07-08 18:17:24

Obviously, had to be lsusb indeed - my apologies.

Arch Linux

#1 2012-07-08 02:17:35

[solved] 4 USB Wifi Adaptors that work out of the box in Arch

#2 2012-07-08 11:54:11

Re: [solved] 4 USB Wifi Adaptors that work out of the box in Arch

#3 2012-07-08 16:10:01

Re: [solved] 4 USB Wifi Adaptors that work out of the box in Arch

#4 2012-07-08 18:17:24

Re: [solved] 4 USB Wifi Adaptors that work out of the box in Arch

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