Network with OEL 5.7 x86_64 install in Hyper-V

When installing Oracle Enterprise Linux 5.7 x86_64 in a Hyper-V 2012 VM, the Linux networking refuses to work with the Hyper-V “Legacy driver” if you have the UEK (unbreakable enterprise kernel) enabled and more than one vCPU.

First, you should always ensure that you add the Hyper-V “Legacy Network driver” to the VM container at the VM creation time to ensure that it will work when you come to install OEL in the VM.

Then, to get around the problem with the networking and vCPUs, disable the UEK kernel and shutdown, then you can add more than one vCPU to the VM.