WiFi not reliable and can't change networks

sixteenkats · #1 24th July 2009, 09:07 PM

Fedora 10 (dual boot w/ XP) on Dell Optiplex with a Dell wireless antenna

I am on a university campus with campus-wide wifi network (so no router). I have a wireless HP printer that I want to be able to print to using an ad-hoc connection. The wireless antenna, networking, and wireless printing are all working in Windows XP (so hardware is OK). However, on the linux side, the wifi is really really finicky.

When I first boot up to fedora, it usually connects no problem to the campus-wide wifi network. If I try to switch to the ad-hoc printer network (which it sees), it will not connect and, furthermore, it will no longer connect to the campus-wide network (and sometimes it doesn't "see" this network at all). It seems that restarting the Network Manager service sometimes helps to reconnect to the campus-wide network, but not always and I can't connect to the ad-hoc regardless.

I'm really at a loss for what to do to fix this. Any help is appreciated!

NOTE: I'm just barely a linux user, and I didn't set up my system - don't assume that I did anything that would be common sense and, if you can, walk me through your suggestions.

sixteenkats · #2 28th July 2009, 11:00 PM

I went through this other post and found the following:

# /sbin/lspci

Quote:

Network controller: Intel Corporation Device 4235

so seems like I need iwlagn (?)

# /sbin/lsmod | grep iwlagn

Quote:

iwlagn 163844 0
iwlcore 137668 1 iwlagn
mac80211 213872 2 iwlagn,iwlcore
cfg80211 32400 3 iwlagn,iwlcore,mac80211

# iwlist wlan0 scan

Quote:

wlan0 Scan completed :
Cell 01 - Addresss: 00:0A:B8:56:27:23
ESSID:"eaglenet"
Mode:Master
Frequency:2.412 GHz (Channel 1)
Quality=47/100 Signal level:-74 dBm Noise level=-93 dBm
Encryption key:off
Bit Rates:5.5 Mb/s; 6 Mb/s; 9 Mb/s; 11 Mb/s; 12 Mb/s
18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Extra:tsf=000002c96910112b
Extra: Last beacon: 3ms ago
Cell 02 - Addresss: E2

9:F9:61:30:F0
ESSID:"hpsetup"
Mode:Ad-Hoc
Frequency:2.437 GHz (Channel 6)
Quality=35/100 Signal level:-88 dBm Noise level=-127 dBm
Encryption key:off
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
Extra:tsf=000008f7ab7bb24a
Extra: Last beacon: 2808ms ago
Cell 03 - Addresss: 00:0A:B8:56:22:93
ESSID:"eaglenet"
Mode:Master
Frequency:2.462 GHz (Channel 11)
Quality=35/100 Signal level:-88 dBm Noise level=-127 dBm
Encryption key:off
Bit Rates:5.5 Mb/s; 6 Mb/s; 9 Mb/s; 11 Mb/s; 12 Mb/s
18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Extra:tsf=0000036a8a2a60f4
Extra: Last beacon: 2611ms ago

eaglenet is the campus wifi. hpsetup is the ad-hoc connection to the printer.

Any suggestions for how to connect to the ad-hoc network and reliably switch back to the campus wifi without having to restart NetworkManager or the computer?

sixteenkats · #3 28th July 2009, 11:37 PM

OK - I have now run through this troubleshooter posted on another thread.

Everything works as expected until:

Code:

iwconfig wlan0 essid eaglenet

It doesn't pause at all and nothing is returned - I just get a new command prompt.

As suggested, I open a new terminal to run:

Code:

dhclient wlan0

The response is:

Quote:

Nothing to flush.

So, to quote from the troubleshooter:

Quote:

If some of these tests fail, then, to repeat myself, the problem is more likely to be with the drivers for the card, and you are most likely to get help by posting on your distribution's forums, remembering to put the card model in the subject line of your post.

What do I do to fix the drivers?

nyjetshead · #4 29th July 2009, 12:40 AM

Right click on the network manager icon in the tray > Edit connections > Wireless >Add

Now create an entry for your Printer SSID called "hpsetup" in Adhoc mode
Tab IPV4 = Shared with other computers
Wireless security tab = NONE

Byway of the tray icon you should be able to switch from your campus WIFI to the printer.

sixteenkats · #5 29th July 2009, 06:42 PM

Quote:

Originally Posted by nyjetshead

Right click on the network manager icon in the tray > Edit connections > Wireless >Add

Now create an entry for your Printer SSID called "hpsetup" in Adhoc mode
Tab IPV4 = Shared with other computers
Wireless security tab = NONE

Byway of the tray icon you should be able to switch from your campus WIFI to the printer.

OK - now I can switch to the hpsetup adhoc network. But switching back to campus wifi is not reliable... restarting Network Manager seems to fix the problem, but this isn't a good longterm solution.

nyjetshead · #6 29th July 2009, 09:05 PM

I would try the F11 live version as a test, if it works then upgrade.
There were changes to the wireless infrastructure that weren't added to F10.

sixteenkats · #7 4th August 2009, 05:28 PM

Quote:

Originally Posted by nyjetshead

I would try the F11 live version as a test, if it works then upgrade.
There were changes to the wireless infrastructure that weren't added to F10.

F11 live seems to solve the problem. I can connect to both the printer and infrastructure wifi and switch back and forth as much as I want. Will try to upgrade. Thanks for your help!