On Tue, Nov 02, 2010 at 02:23:23AM +1300, Jammer wrote:
> I'm experiencing problems setting up an OpenBSD box as a
> firewall/Wireless Access Point(...)
>
> Firstly my setup:
> * I've tried this using OpenBSD v4.1, v4.6 and a 4.8 snapshot from
> 29/10/20 all with similar results.
Just install 4.8 or -current.
> * I've tried various different wireless cards based on either the
> Prism (wi0) or Ralink 2561 (ral0) chipsets.
There are a lots of caveats about Host AP mode in wi(4) (from -current):
(...)
Host AP In this mode the driver acts as an access point (base
station) for other cards. Only cards based on the
Intersil chipsets support this mode. Furthermore, this
mode is not supported on USB devices.
(...)
HARDWARE
Cards supported by the wi driver come in a variety of packages, though
the most common are of the PCMCIA type. In many cases, the PCI version
of a wireless card is simply a PCMCIA card bundled with a PCI adapter.
(...)
USB support is still experimental and the device may stop functioning
during normal use. Resetting the device by configuring the interface
down and back up again will normally reactivate it.
(...)
CAVEATS
Not all 3.3V wi PCMCIA cards work.
IBSS creation does not currently work with Symbol cards.
The host-based access point mode on the Intersil PRISM cards has bugs
when used with firmware versions prior to 0.8.3 and is completely
unusable with firmware versions prior to 0.8.0 and 1.4.0-1.4.2.
Software WEP is currently only supported in Host AP and BSS modes.
Furthermore, software WEP is currently incapable of decrypting fragmented
frames. Lucent-based cards using firmware 8.10 and above fragment
encrypted frames sent at 11Mbps. To work around this, Lucent clients
with this firmware revision connecting to a Host AP server should use a
2Mbps connection or upgrade their firmware to version 8.72.
Host AP mode doesn't support WDS or power saving. Clients attempting to
use power saving mode may experience significant packet loss (disabling
power saving on the client will fix this).
Support for USB devices is buggy. Host AP mode and AP scanning are not
currently supported with USB devices.
>From ral(4):
(...)
CAVEATS
(...)
Host AP mode doesn't support power saving. Clients attempting to use
power saving mode may experience significant packet loss (disabling power
saving on the client will fix this).
Some PCI ral adapters seem to strictly require a system supporting PCI
2.2 or greater and will likely not work in systems based on older
revisions of the PCI specification. Check the board's PCI version before
purchasing the card.
I've never set up an AP myself, but it's not clear that you are aware of
these possible issues from your message.
> * I've used 4 different machines, admittedly all low horsepower
> machines, from 400MHz PII to 1.2GHz Athlon
> * I've tried configuring the interface in both "ibss" and "hostap"
> mode. I'm aware of the caveat regarding hostap mode and power saving
> mode in the client and have ensured that the clients (various WinXP
> times 2, and Brother wireless enabled printer) have this disabled
> but the packet loss occurs in both ad-hoc and hostap modes anyway.
> On each occasion I get anywhere up to 75% packet loss or long
> periods of several tens of seconds where the wireless link is down.
> Often the clients are completely unable to associate with the access
> point/peer and the link is most unstable. I have tried this with the
> two machines side by side and at a distance of >10m but even with a
> link of only a few feet I still get packet loss.
>
> I've tested by pinging both ends both individually, and
> simultaneously, and the packet loss occurs in both directions.
> At the same time, I can use the same wireless cards in a Windows XP
> machine and get zero packet loss and a completely stable link in an
> ad-hoc network so I'm sure that the hardware is OK and the wireless
> radio does work.
> I'm afraid I don't have my dmesg handy (...)
*Always* include a dmesg if you're having hardware issues.
Joachim
--
PotD: x11/lupe - real-time magnifying glass for X11
http://www.joachimschipper.nl/
