Do a search for Hackintosh Vietnam Tool and down load it. Unzip and you have a .pkg file which you run with installer.
Opens up an installer window with choices. click on all the accept buttons which will take you to a window listing Chameleon: Clover: Kexts: and so on. Click on Kexts, then on Network, then on Ethernet. there is a choice box for NullEthernetInjector, which you can check or not. I haven't found where it does anything, but the explaination at the bottom box says it is supposed to help with AppStore.
next choose Realtek, and then check RealtekRTL8111, which is the kext for your Ethernet. I have the same one.
click install and it should get your wired ethernet going.
While you are in this thing, Wander around in it and choose whatever else you need for getting your install of Mavericks going. It is supposed to work on Yosemite also, but I have not been successful in getting Yosemite to install yet, so can not report on that.