After discussing the technology options one has when trying to get a packet across the network, we dived deep into two interesting topics:

• How do you combine packet forwarding at multiple layers of OSI stack (multi-layer switching)?
• What happens when you do layer-N forwarding over layer-M transport core where N <= M (example: IPv6 packets over IPv4 packets) aka tunneling?

You’ll find more details (including other hybrids like Loose Source Routing) in Multi-Layer Switching and Tunneling video.