I want to use an "USB Modem" (3G) for internet and a local area network (LAN) (Ethernet) at the same time. The "USB Modem" is a device of the same kind of a Huawei 3G USB modem. When I turned the USB modem ON, the ethernet local network (wired) is not disconnected. However, when I do that I can not anymore access local network devices. For example, I can not ping the servers that are in my ethernet (wired) when I'm connected to the internet using the USB modem. What I want is just to use USB modem for internet while I can access the devices (servers) on my ethernet LAN. Thank you!