So a vMKernel interface is a virtual network adapter used by the host hypervisor to communicate for Management, vmotion...
When you click on "add networking" you should select "Virtual Machine" and then on the next screen select "New Virtual Switch". You will assign a network label like ISP1 or ISP2, and associate a physical adapter to the virtual switch. Then connect the physical adapter to your ISP equipment or core network.
Repeat until you have a network label and new virtual switch for Core, ISP1, and ISP2.
In this case you need to create NICs for your guest operating system to use. If you right click on the virtual machine and select "edit settings" you will have the option to add hardware. You can add a NIC, then select the network labels you created earlier like ISP1. Once you have created the additional NICs go into the guest OS to assign the IP address
