That’s not how NVIDIA’s solutions work; if you connect a DGX system to a NVLINK switch it will talk NVLINK if you connect it to another via Infiniband it will speak Infiniband, if you do PCIe Direct Attach it would talk that too and if you connect it via Ethernet it you guessed it talk Ethernet with RDMA and all the bells and whistles to boot.
NVLink either talks native NVlink to itself when you are using NVlink switches either intra-server or intra-rack or;
It can talk PCIe over NVlink when talking to a PCIe endpoint.
Or you can run Infiniband or Ethernet on top of it and talk to w/e is on the other side.
Gaudi isn’t that different remember Ethernet != TCP/IP.