[Gllug] Assessing WLAN capabilities

[DL Neil]

Hi Jan, good to hear from you.

Jan Henkins wrote:
>   Hello there,
> 
> On 02/09/10 09:45, DL Neil wrote:
>> Are tools available which list a (Linux) machine's WLAN capabilities?
>> (I'm assuming that it is a combination of h/w and s/w)
...

>> Taking a step back from there, how can I tell that a machine will only
>> run 802.11B cf B and G? (without opening-up the box, if then)

> I would boot from something like the System Rescue CD 

=are you looking over my shoulder? I was just downloading 1.5.8 (newly 
released in July) for another job (upgrading a machine to dual-boot with 
the aim of producing another 'convert' to our cause...)


=actually, needing to keep my email/machine running for conversations 
with guys in the States (go home...please...) I 'cheated' and found lshw 
in rpmforge (it's not in standard CentOS repositories), and started 
having a 'play'
- didn't know there is a -html option (with such pretty colors!)
- nor indeed that there is a gui add-on (which has logos and presents 
the data in 'panels' cf 'paragraphs'). Ooh la la!
(am not sure if it will make a difference to run without CentOS, but 
will test my download/burn shortly, and ensure that the 
presented-information is no different...)


> (http://www.sysresccd.org) or similar, and use lshw in order to check 
> out named chipsets. With a reasonable amount of luck, you should be able 
> to see something like this (my machine is an Acer TM 4670) as part of 
> the very verbose lshw output:
...

=yes, and mine is fairly similar (but with gray hairs):
...
            *-network:0
                 description: Wireless interface
                 product: Prism 2.5 Wavelan chipset
                 vendor: Intersil Corporation
                 physical id: 5
                 bus info: pci at 0000:01:05.0
                 logical name: wifi0
                 version: 01
                 serial: 00:20:e0:4d:78:94
                 width: 32 bits
                 clock: 33MHz
                 capabilities: pm cap_list logical wireless ethernet 
physical
                 configuration: broadcast=yes driver=hostap 
driverversion=0.4.4-kernel firmware=1.3.6 ip=192.168.15.91 latency=32 
multicast=yes wireless=IEEE 802.11b
                 resources: irq:11 memory:80300000-80300fff(prefetchable)
...

=which brings me to the same question contained in my response to Rich's 
reply, the listing of "IEEE 802.11b" under "configuration" makes my 
first thought that this is its 'current status', whereas if it were 
listed under "capabilities" I would be quite sure that this is as good 
as it gets!


> In general, if your card supports B, you have an even chance of the 
> hardware actually supporting WPA. If your card supports G, the chances 
> of it *not* supporting WPA in any form is vanishingly slim. In some 

=this is where I run out of knowledge and my Linux Bible-type books have 
not actually helped (v.low on wireless content):
- some parts of 'wireless' are hardware, and some are implemented in 
software (and yes you add firmware, below). Where is the boundary?
(I'm used to .mil stuff where encryption might well be 'hardware', eg a 
*PROM chip or a gate-array, particularly in a 'voice' transceiver, but I 
don't expect that Linux works that way...)

=obviously whether the device is 802.11a, b, g, or n is physical; but 
isn't the WEP cf WPA implemented in software? When it comes to 
implementing AES cf TKIP (sticking with 'simple' WPA, for a moment) 
surely that bit is software???
(will appreciate directed reading! and yes, I recognise that 
enc/decryption would incur a possibly-expensive processing overhead as 
the complexity/efficacy rises)


> cases, you might need some form of a binary blob from the chipset vendor 
 > in order to load firmware into the wlan card before it can work

=unfortunately (pre-Lenovo) IBM have not been overly-supportive, even 
our M$ colleagues are expected to buy a new CD if the original Windoze + 
hidden 'restore partition' should 'disappear', and may not even be able 
to do that these days! Linux support back then was non-existent and 
totally within the community/after-market.
(NB I haven't (yet) looked at the release notes to see if there were any 
'wireless' updates when the machine firmware was updated...)


> properly. In such cases, also depending on the "Linux-friendliness" of 
> the chipset vendor, you might be forced to go down the ndiswrapper route 
> with all it's trials and tribulations in order to get the card to work 
> with the Windows drivers. Not nice, but sometimes one has no other choice.

=there is a Windows download. Can't recall if it uses NDIS. This m/c has 
been totally Linux since hdd replacement proved such a hassle.

=Just in case I wasn't clear, the wireless 'works' currently but it is 
wide-open; the questions relate to figuring out just how much security I 
might implement before the Thinkpad says 'wot?', other than by my 
current fumbling trial-and-error...

=Being used to the sorts of listings that lshw gives (some of us do heed 
the warnings to check the h/w compatibility BEFORE attempting to 
install/migrate from 'the dark side'!), I was/am still hoping that there 
is some useful utility which will 'assess' the capabilities of the 
wireless unit, and illuminate...


>> but how do I find out if the current CentOS version is 5.3, 5.4, or 5.5...?
> You will find that info here:
> Hope this helps!

=Yes it did. Many thanks.

=Regards,
=dn


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