While the Windows CE device’s USB client port is connected to a host (e.g. for debugging), the network connection is not accessible.
Reason: The USB client connection creates a virtual CoM port CoM0 and an additional network connection through CoM0. The Windows CE device’s network traffic is then routed to CoM0 by default.
Use the Windows CE command line to change the routing table:
route print com0
Look at the CoM0: row in the interface list, and remember the number shown in the first column <i>.
route delete 0.0.0.0 IF <i>
Where <i> is the number taken from step 1.
Repeat these steps each time you disconnect and re-connect the USB cable.