My network is completely flat, all on one hub, and has no segmentation. Where should I place my NIDS? If I already have NIDS in my network, do I also need HIDS? What about the reverse—I have HIDS on a...

My network is completely flat, all on one hub, and has no segmentation. Where should I place my NIDS?

If I already have NIDS in my network, do I also need HIDS? What about the reverse—I have HIDS on a couple of servers; do I still need NIDS?