BeagleBone & weird wifi problem

I’m using a Netgear WNA1000M USB wifi dongle on a BeagleBone rev.A3 connecting to an open AP. It’s kinda working, but stops if I unplug the Ethernet connection!

Some details:

  • The dongle presents as wlan1.
  • Drivers (rtl8192cu) seem to be installed okay.
  • My /etc/network/interfaces file includes:

auto wlan1
iface wlan1 inet dhcp
wireless-essid Lefty

When I boot up, ifconfig shows that wlan1 has obtained an IP of while eth0 is on - all of which is as I’d expect.

I can ping from elsewhere on the network. I have also ssh’d into the BeagleBone via

Here’s the output of iwconfig:

wlan1 IEEE 802.11bgn ESSID:“Lefty”
Mode:Managed Frequency:2.412 GHz Access Point: E2:91:F5:02:C1:3A
Bit Rate=150 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr=2347 B Fragment thr:off
Encryption key:off
Power Management:off
Link Quality=69/70 Signal level=-41 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

But, if I remove the Ether cable, becomes unreachable.

If I boot the 'bone without the Ether attached, the wifi fails to come up (no light).

What am I missing? Any help appreciated.