DebConf11/Wireless

So far we have a Buffalo which is doing DHCP and NAT for the main network and acting as an AP covering the main auditorium (rather uselessly until we can use it) and a second AP acting as a bridge covering the upstairs hacklab(s).

We should have more soon when we start to setup a real network tomorrow. Or maybe even tonight.

Using the debconf wireless

The SSID is debconf and password debconf11 .

Hardware list

• 11x Buffalo WHR-G54
• 1x NetGear DG8343G v3

Access Point list

AP	Channel	Location	MAC Address	Notes
B131	6	Round Room	00:0D:0B:83:7C:68	2.4, txpower 10
B132	1	Auditorium - Left	00:0D:0B:83:7F:30	2.4, txpower 11
B133	11	Round Room	00:0D:0B:83:7F:74	2.4, txpower 10
B134	6	Auditorium - Behind stage	00:0D:0B:83:6D:F4	2.4, txpower max (used to be 11)
B135	11	Auditorium - Right	00:0D:0B:83:82:A2	2.4, txpower 11
B136	6	Upstairs Hacklab Middle	00:0D:0B:83:75:54	2.4, txpower 12
B137	11	Gallery Hacklab in Window	00:0D:0B:83:6D:78	2.4, txpower max (used to be 11), wpa+wpa2 (used to be wpa2 only)
B138	6	Inside Reception Desk	00:0D:0B:83:87:64	2.4, txpower 10
B139	1	Gallery Hacklab on Switch	00:0D:0B:83:90:AA	2.4, txpower 8
B140			00:0D:0B:83:82:46	2.4, in stock
B141	11	Upstairs Hacklab in door	00:0D:0B:83:79:68	2.4, txpower normal (used to be 8)

Documentation for the OpenWRT setup at DebConf11

This page describes the accesspoint configuration for DebConf11. We're using the Backfire version of OpenWRT.

The accesspoints will be bridging to provide WPA encrypted wireless on debconf . On the b+g network we'll use the channels 1, 6 and 11. We avoid interference as much as possible by turning down the power on the APs, and it will very likely also help for people to turn down the power on their laptops to something like 10dBm.

Buffalo Configurations

We're using the standard images from Backfire 10.03.1-rc5 here. On the buffalo the needed file is the broadcom 47xx .trx file, which uses the open source b43 drivers.

/etc/config/network

config 'switch' 'eth0'
       option 'enable' '1'

config 'switch_vlan' 'eth0_0'
       option 'device' 'eth0'
       option 'vlan' '0'
       option 'ports' '1 2 3 4 5'

config 'switch_vlan' 'eth0_1'
       option 'device' 'eth0'
       option 'vlan' '1'
       option 'ports' '0 5'

config 'interface' 'loopback'
       option 'ifname' 'lo'
       option 'proto' 'static'
       option 'ipaddr' '127.0.0.1'
       option 'netmask' '255.0.0.0'

config 'interface' 'lan'
       option 'type' 'bridge'
       option 'ifname' 'eth0.0'
       option 'proto' 'dhcp'
       # option 'proto' 'static'
       # option 'ipaddr' '192.168.1.1'
       # option 'netmask' '255.255.255.0'

config 'interface' 'wan'
       option 'ifname' 'eth0.1'
       option 'proto' 'static'
       option 'ipaddr' '192.168.1.1'
       option 'netmask' '255.255.255.0'
       option 'dns' '8.8.8.8'  # Google

/etc/config/wireless

config 'wifi-device' 'radio0'
	option 'type' 'mac80211'
	option 'macaddr' '00:0d:0b:83:75:55' # One more than MAC on side of device
	option 'hwmode' '11g'
	option 'disabled' '0'
	option 'channel' '11'    # adjust channel to suit where the AP will be
	option 'txpower' '11'   # adjusted when managing the AP later
	option 'distance' '20'  # adjusted when managing the AP later

config 'wifi-iface'
	option 'device' 'radio0'
	option 'network' 'lan'
	option 'mode' 'ap'
	option 'ssid' 'debconf'
	option 'encryption' 'mixed-psk+tkip+ccmp'
	option 'key' 'debconf11'

/etc/config/system

config system
	option hostname	bXXX
	option timezone	UTC

config rdate
	list server ac-ntp0.net.cmu.edu
	list server ptbtime1.ptb.de
	list server ac-ntp1.net.cmu.edu
	list server ntp.xs4all.nl
	list server ptbtime2.ptb.de
	list server cudns.cit.cornell.edu
	list server ptbtime3.ptb.de

Flashing

Buffalo

#!/bin/sh

IP=${1:-"192.168.11.1"}

ME="`echo ${IP} | cut -f1-3 -d.`.254"
sudo ip addr add ${ME}/24 dev eth0

echo "Unplug power, press button on top and replug power"
echo "Release the button when the upload starts after about 3 seconds"
CONFIG=config
#atftp --trace --option "mode octet" -p -l openwrt-brcm-2.4-squashfs.trx ${IP}

CONFIG=config26
atftp --trace --option "mode octet" -p -l openwrt-brcm47xx-squashfs.trx ${IP}

sudo ip addr del ${ME}/24 dev eth0

sudo ip addr add 192.168.1.254/24 dev eth0

echo "Waiting for flashing"
sleep 50
echo "Waiting for reboot"
sleep 50

echo "Telnet to assign passwd"
telnet 192.168.1.1

## Not needed for now, since we're using DHCP
# echo "Edit to assign IP address"
# gvim -f ${CONFIG}/network
ping -c1 192.168.1.1 >/dev/null
MACADDR="`arp -i eth0 | grep 192.168.1.1 | cut -c34-51`"


echo "Edit to assign wireless channel"
gvim -f ${CONFIG}/wireless

echo "Edit to assign Hostname"
gvim -f ${CONFIG}/system

echo "Push ssh authorized_keys to device"
scp ~/.ssh/id_rsa.pub root@192.168.1.1:/etc/dropbear/authorized_keys

echo "Push configuration to device"
scp ${CONFIG}/* root@192.168.1.1:/etc/config

scp kmod-ipv6_2.6.32.27-1_brcm47xx.ipk root@192.168.1.1:
ssh root@192.168.1.1 opkg install kmod-ipv6_2.6.32.27-1_brcm47xx.ipk

sudo ip addr del 192.168.1.254/24 dev eth0 2>/dev/null

Your .ssh config

You may want to add this stanza to your own ~/.ssh/config to disable host key checking on 192.168.1.* so that you can ssh into multiple APs as you're flashing them without getting annoying warnings about the host key (of course) being changed...

Host 192.168.1.*
  StrictHostKeyChecking no
  GlobalKnownHostsFile /dev/null
  UserKnownHostsFile /dev/null

Issues

Issues Log

Add your issue here, including the MAC address of the AP you saw the issue with, the date & time, and any other useful information you can think of. Then tell karora on IRC your own wireless MAC address.

See also

• DebConf11/Network

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