My computer has 2 ethernet ports and 1 wireless port. One of the ethernet ports (eth5) and the wireless port (wlan0) are both configured to connect to a network server, and the other ethernet port (eth4) is configured to connect to a local network switch for communicating with some local devices. The route table of the computer is shown in this screen capture: My question is that, how I could change the sequence of the gateways with the network-manager in ubuntu, so that the gateway of wlan0 will be used before the eth4's. Otherwise when I unplug the cable from eth5, I will lose connection to the network (the gateway of eth4 will be used by default).
I tried editing the /etc/network/interfaces file, but it conflicts with the network-manager, and it can not handle the dynamic events (e.g., when network cable is plugged or unplugged), meaning that its settings are static, while the network-manager can handle these things perfectly, and change the network configurations adaptively, so I would like to find a solution for this problem with network-manager.
The os is ubuntu 13.04 32bit. Thanks for viewing and I will appreciate for any advice!