I’m using RobertCNelson’s 4.1.10-bone16 kernel in an embedded application where I use a PHP script to configure /etc/network/interfaces to allow connection to a wi-fi network. Worked perfectly until I encountered an open network (no password required). I’ve since replicated the failure on a wide range of open networks, including when I change a working router from WPA to ‘none’. I would really like to be able to connect to open networks. We have no control over the networks that we encounter - just this week at a trade show, for instance.
Working interfaces file stanza with wpa-psk:
auto ra0
allow-hotplug ra0
iface ra0 inet dhcp
wpa-ssid VECS2
wpa-psk "passphrase"
Failing stanza for same router configured with no wi-fi security:
auto ra0
allow-hotplug ra0
iface ra0 inet dhcp
wireless-essid VECS2
Logs (or command line) show dhclient failing to get a response:
DHCPDISCOVER on ra0 to 255.255.255.255 port 67 interval 5
DHCPDISCOVER on ra0 to 255.255.255.255 port 67 interval 14
DHCPDISCOVER on ra0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on ra0 to 255.255.255.255 port 67 interval 15
DHCPDISCOVER on ra0 to 255.255.255.255 port 67 interval 16
DHCPDISCOVER on ra0 to 255.255.255.255 port 67 interval 3
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
Possible clue (or red herring) - iwconfig shows previous successful ESSID and zero signal after failed attempt at open network:
ra0 Ralink STA ESSID:“cld” Nickname:"MT7601STA"
Mode:Auto Frequency=2.447 GHz Access Point: Not-Associated
Bit Rate:1 Mb/s
RTS thr:off Fragment thr:off
Encryption key:off
Link Quality=100/100 Signal level:0 dBm Noise level:0 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0