hostapd issues and questions

Sergio Ammirata ammirata
Tue Jan 21 01:31:29 PST 2003

> -----Original Message-----
> From: hostap-admin at [mailto:hostap-admin at] 
> On Behalf Of Jouni Malinen
> Sent: Tuesday, January 21, 2003 12:17 AM
> To: hostap at
> Subject: Re: hostapd issues and questions
> On Sun, Jan 19, 2003 at 12:09:35PM -0500, Sergio M. Ammirata wrote:
> > 1) Changing the mac address of the wlan0 interface using ifconfig 
> > breaks routing (you can link but the tcp/ip layer does not 
> work). This 
> > happens only with hostapd enabled.
> Was hostapd running when you changed MAC address? You must 
> restart hostapd after this change.

Hostapd is not running when I change the MAC address.

Here is the script I use:

echo -n "Starting wlan0: "
insmod hostap_crypt
insmod hostap_crypt_wep
insmod hostap
# Start in infrastructure mode so that the old MAC Address does not get
insmod hostap_cs essid=test iw_mode=2 channel=6 
echo -n "Initializing pcmcia"
/etc/rc.d/init.d/pcmcia init
# Set the to the same mac as the ethernet interface
HWADDR=`/sbin/ifconfig eth0 | sed -n 's/.*HWaddr\(.*\)/\1/p'`
ifconfig wlan0 hw ether $HWADDR
iwconfig wlan0 mode master
# Configure Wireless parameters
iwconfig wlan0 txpower 23
iwconfig wlan0 sens 3
iwconfig wlan0 nick $hostname
# Disable bridging (use ethernet bridges instead)
iwpriv wlan0 bridge_packets 0
iwpriv wlan0 host_roaming 1
# Now that everything is configured bring up the wlan0 interface and
enabled the hostap daemon
ifconfig wlan0

# Start user space daemon
hostapd /etc/hostapd.conf

echo "Done."

> > 2) Without hostapd there is wlan0 and wlan0wdsx. Now we 
> have wlan0ap 
> > and wlan0sta as well. How are we supposed to setup Ethernet 
> bridging 
> > now? Do we include all three in the bridge (wlan0, wlan0ap and 
> > wlan0sta)?
> wlan0ap should not be included in bridge setup at all. It 
> used only for management frames (802.11 auth/assoc, 802.1X 
> EAPOL frames) within that one AP. wlan0sta is an experimental 
> device used for station mode operations with another AP if 
> assoc_ap_addr is set. It does not support layer-2 bridging 
> (just like any other "normal" station mode card), so it 
> should not be included in bridge setup.
> > 3) Has the functionality of wlan0wdsx changed? When and why would I 
> > use wlan0sta?
> No, wlan0wds# work as before. You could potentially use 
> wlan0sta as a wireless uplink with IP routing (and possible 
> Proxy ARPing).

I noticed that wlan0sta does not have an independent essid. When you
change it on wlan0 it also changes for wlan0sta. If the destination MAC
for wlan0sta has a different essid than wlan0, will it still link?

> > 4) With hostapd active iwspy no longer reports any info on wds 
> > neighbors. How can I found out the strength of the links?
> That is not implemented yet.

Will it make it into this release?
Is there an alternate way of measuring the link speed or to even found
out that we are linked to neighbors other than pinging?

> -- 
> Jouni Malinen                                            PGP 
> id EFC895FA
> _______________________________________________
> HostAP mailing list
> HostAP at

Thanks in advance,


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