Strange USB Networking problem on the BeagleBone

Hello all,

I am running Arch Linux on my BeagleBone; I am encountering a strange problem when trying to
set up USB networking.

I started usb networking on the BeagleBone by executing:

modprobe g_ether

I then manually assigned IP addresses to both ends (host PC: 192.168.7.1, BeagleBone: 192.168.7.2) - it worked
fine and I am able to see the interfaces in the output of “ifconfig” on both BeagleBone and host PC.

But when I tried pinging the host PC from the BeagleBone, I am getting “destination unreachable” error.

Upon running “tcpdump -i usb0” on the host PC, I discovered that ARP packets are being sent out from the BeagleBone
to the PC (and received by the PC, as shown by increasing Rx count in output of ifconfig), but no response is being
sent out from the PC (no increase in Tx count on the PC)

I then manually populated the arp cache (using arp -s) on both the PC and the BeagleBone - now, “tcpdump -i usb0”
on the host PC shows me that ICMP packets are being sent from the BeagleBone (and received by the PC, as indicated
by the increasing Rx count in the output of ifconfig), but the host PC is not responding.

I wrote a simple UDP client server-program - the client program on the BeagleBone is able to send data to the UDP
port on the server PC, but the PC is unable to send data back to the BeagleBone (this was done after populating the arp
cache on the BeagleBone).

The problem seems to be that no matter what, packets are not being sent out through the host PC’s usb interface. The
“ip” command shows the usb ethernet link to be in the “NO-CARRIER” state on the PC.

The kernel running on the BeagleBone is 3.2.0. I used a netbook (running Ubuntu, kernel 3.0.0-12-generic) as well

as a PC (running Debian, kernel 2.6.32 and Arch kernel 3.2) for the experiment and the behaviour is exactly the same - no packets are
being sent out from the host PC/netbook when the BeagleBone is running Arch.

Any pointers as to what might be the cause of the problem will be highly appreciated!

Thanks and Regards,
Pramode