hostapd

Recently I learned that my netbook (a 2012 Acer Asprire One) could be configured as a home WiFi access point, with very little effort.

This trusty little computer with a really awful keyboard saw me through the hard times when my untrustworthy Thinkpad broke down. These days it is hooked to the ISP’s router via ethernet, and is always on, functioning as a mediatomb and owncloud and what not server. It runs Debian stable.

The ISP’s router plays rather quite poorly with Windows computers and Windows phones – which is really surprising. Running hostapd in the netbook and using that as the access point solved that problem nicely.

I needed some tiny changes in /etc/network/interfaces for a bridge interface setup:

auto lo br0
iface lo inet loopback

allow-hotplug eth0

# Bridge setup
iface br0 inet dhcp
        bridge_ports eth0 wlan0

This is what /etc/hostapd/hostapd.conf looks like:

interface=wlan0
driver=nl80211
bridge=br0

logger_syslog_level=3

country_code=US
ieee80211d=1

ctrl_interface=/var/run/hostapd
ctrl_interface_group=0

ssid=<whatever>

hw_mode=g

channel=1

wme_enabled=0
macaddr_acl=0
auth_algs=1

wpa=2
wpa_passphrase=<whatever>
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

A few things of note:

• If you want to try this out, you might want to run “/sbin/iw list” and make sure that AP is listed under “Supported interface modes”. Mine has these lines:

[...]
Supported interface modes:
         * IBSS
         * managed
         * AP
         * AP/VLAN
         * monitor
[...]

• To verify that hostapd configuration is error-free, this command was useful: /usr/sbin/hostapd -d /etc/hostapd/hostapd.conf

• The Android app Wifi Analyzer helped in scanning the WiFi “neighborhood” and picking up an interference-free channel.

• Arch wiki has a lot of details.