question on ethernet logical link protocol

Hei, I am facing a problem on my WM6 device. I am using a USB-to-LAN
adapter with it, I found if I unplug and re-plug the cable from the
adapter, in most cases, my downloading will be able to resume.
The problem is if the device is connected to a Cisco Swith, the
dwonloading will not be able to resume, the connection will eventually
get canceled by server.

After using Sniffer to watch the traffic, I notice that, when the
device is connected to a Cisco Switch, on re-plug the cable, the
switch will send a few Cisco Discovery Protocol packet, which is using
ethernet LLC protocol, while all other traffic using Ethernet II
protocol only.

Could the ethenet LLC causing my connection can not be restored, or it
take too long to restore but server can not wait anymore?

Does anyone know which driver or library process ethernet packet, who
process the ethernet Logical Link Control protocol in Windows Mobile
6?

Thanks