I m working on clustering . When I connect two laptop through Ethernet connection or cable connection laptop can not connect with wifi . I have set up ubuntu 14.04 on Accer laptop .. I need to connect both Ethernet and wifi at the same time on ubuntu .. Basically at present It can connect with one connection .
This question has been answered at How to set up dual wired and wireless connections?
Basically, you can only have one default gateway. Ubuntu is going to choose wired e-net over wireless every time because wired is faster. If the wired and wireless connections go to completely different networks (e.g. a secured e-net network at work and an insecure wireless network for guests) the above answer explains in detail how to accomplish what you want.