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<font face="sans-serif">Hello all,<br>
<br>
Just sharing some info with the list - in case anybody will find
it useful.<br>
<br>
Some of you might remember that I've mentioned a while ago that
I'm using, as my main wifi access point, an ageing Compaq laptop
with it's original, internal Broadcom wifi card and <a
href="http://hostap.epitest.fi/hostapd/">hostapd</a> on the
software side. This is not ideal from some points of view, as the
signal is not great - the wifi card only has the internal laptop
aerial to work with. However, I like the idea of integrating my
server and wifi access point in one. And using Linux for both. Two
years and a half ago when I've set this up it's been quite a pain,
with very little information available on how to setup hostapd and
even less information on which cards can support host/master mode,
and even more crucially, which ones have a kernel driver
implementation which will actually work in host/master mode. At
the time a lot of the implementations/drivers seemed broken.<br>
<br>
Fast forward to nowadays - when I'm in the process of replacing
the server with an Atom board, "proper" server (well, at least a
bit more proper then using a laptop). I intended to use the same
trick, with hostapd, instead of having yet another router/access
point plugged into power separately. The first bit of good news is
that the kernel support for master mode has expanded quite a bit.
As a rule of thumb, all Intel cards are no good for AP mode (from
hardware design, if I remember correctly, so they will never
support master/host mode). On the other hand, it looks like almost
the majority (or at least a large proportion) of Atheros and
Broadcom chipsets are a good bet. Details are on the <a
href="http://linuxwireless.org/en/users/Drivers">kernel wireless
pages</a> (under the "AP" column).<br>
<br>
I've tried first a recent <a
href="http://www.netgear.co.uk/home/products/wireless-adapters/simplesharing/WNA1100.aspx">Netgear
WNA1100</a> (N150). Although the <a
href="http://linuxwireless.org/en/users/Drivers">kernel wireless
pages</a>, which are a really good starting point, lists the
Atheros chip in this as being supported and having host/master/ap
support, I just couldn't get it working even for basic wireless.
The kernel would complain about not being able to reset the
chipset, or something like that.<br>
<br>
I was about to go out and try to buy something else, when it
crossed my mind that I might have some old adapters knocking
about. One of them is an old US Robotics <a
href="http://www.usr-emea.com/support/s-prod-template.asp?loc=unkg&prod=5422">USR805422</a>
usb adapter. This has an Intersil/Prism chipset - and the last
time I looked at it few years ago, it didn't even have basic
wireless support in the kernel. To my surprise, it now not only
has normal wireless support, it is supported in access mode as
well. Once the correct firmware was copied into /lib/firmware, it
actually got recognised straight away. After compiling and
installing hostapd, it started working without problems. I bridge
wlan0 and eth1 (my internal ethernet interface) so that I can run
a common dhcp server and address pool on both of them - just like
a wifi access point/router does.<br>
<br>
To my surprise, the signal out of this adapter is stronger not
only than my old Compaq laptop (turned wifi AP), but also stronger
then a brand new Netgear router I have around. And I haven't even
gotten round to cracking it open to see if it has one of those
tiny aerial connectors to attach an external antenna to (by the
way, the Netgear adapter I've mentioned above - WNA1100 - looks
like it has one of those connectors - it can just be spotted
through the ventilation openings).<br>
<br>
Hostapd has support for a variety of cool stuff - including
internal EAP server, external RADIUS server, multiple PSK
phrases/passwords (based on MAC addresses), multiple BSSID's etc.
It is even possible to change the transmit power of the adapter
(up to legally permitted limits, depending on which country is
specified in hostapd.conf) using iwconfig.<br>
<br>
I worked out that I could even use one of those active usb
repeater cables to have the adapter placed high up in some crazy
place to make the most of the signal if need be. I haven't had
this setup working for any significant period of time yet - so
can't comment on reliability. There might be glitches. I will have
to run some speed tests - as the old setup, although reliable,
could never achieve maximum throughput even at close range.
However, hostapd itself has been very good over the last 2.5
years.<br>
<br>
Maybe some of the above has become easier then when I tried it
first time because, well, because I've done it a few times now
:-). But there is definitely more documentation about hostapd
around and the kernel support is a lot better.<br>
<br>
Just thought it might be of interest to some people out there.
Hope you are all keeping well.<br>
<br>
Sebastian<br>
<br>
<br>
<br>
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