Intermittent wireless

[John McKendry]

Duane Morin wrote:
> 
> Ok, I thought I had this but maybe not.  Got a Netgear MA401 wireless
> pcmcia card that used to work fine on my thinkpad with mandrake 8.
> 
> Now I've got it recognized and setup as an orinoco/prism2 based card and
> it works (the fact that I'm ssh'd into my other machine from my laptop
> proves it :)).  However it doesnt seem to work consistently.  What I mean
> by that is if I'm downloading something it'll just hang, and then suddenly
> I'll have a bunch of "no route to host" and ifconfig will show me that I'm
> throwing errors like mad.  But i do an ifdown and ifup, and I'm
> back...temporarily.
> 
> This shouldn't have anything to do with the strength of the wireless
> signal, as it happens when I'm not even moving.
> 
> Suggestions?  What's it mean when it works, but not well?  Is the
> orinoco/prism driver not the best one?  I dont have a full kernel source
> tree loaded so I'm leery of anything that starts out with building a new
> module...;)
> 
> Duane
> 
 Having fussed with a big handful of Prism-based cards on desktops, laptops,
and handhelds, I am very hesitant to get started on this, but since you haven't
gotten any other replies (at least on-list), I'll offer what I know:

 There are at least 4 different drivers available for Prism cards: wvlan,
orinoco_cs, hostap, and linux-wlan-ng . The wvlan driver is old and out of fashion,
as far as I can tell. The orinoco_cs is old and stable; it's the one I use,
and it works well for me. I don't load it up much, though. The linux-wlan-ng
driver is recent, well-maintained, and works quite well for most people and
most cards; its downside is that it does not play well with Wireless Extensions,
the "iwconfig" and "iwpriv" tools for configuring the interface, so you have
to learn a fairly daunting set of not-too-well-documented commands with long
parameter names to get your card set up. The hostap driver is recent, well 
maintained, reputed to work well, and works with iwconfig, but sadly it
requires kernel support that is not compiled into the standard Red Hat kernel.

 For the kind of problem you're experiencing, where the card works OK some/most of
the time, the common fix I see on the mailing lists is "try the <whatever you're
not already using> driver". Since you're not in the mood to build a new module,
you probably don't want to build a new kernel, so your choice is the linux-wlan-ng
driver, despite the command-language nuisance. You can get a prebuilt RPM
from http://prism2.unixguru.raleigh.nc.us/ . Absolute Value Systems, the company
that created and supports the driver, has a home page at http://www.linux-wlan.com/ ,
and there is an active mailing list for support.

For completeness, I'll add a link to http://hostap.epitest.fi/ for authoritative 
information and latest source for hostap. If you google for "hostap" and "rpm"
you will find some tantalizing-looking links, but I can't get most of them to
work. Apparently there's a guy in Portland, OR, who has gone to the trouble of
building and RPMing a hostap-supporting Red Hat 9 kernel, as well as the hostap
driver itself. the driver RPMs are at http://www.cat.pdx.edu/~baera/apt/ , but
I can't find the kernel RPMs. (I can find pointers, but the pages don't seem to
be there. This may be temporary.)

John