Which of the following is NOT part of the IP forwarding process?

The correct choice pertains to the fundamental steps involved in the IP forwarding process. In IP forwarding, the primary goal is to direct packets from one network to another based on the destination IP address.

Performing a longest match lookup for the destination IP address is crucial as it helps determine the best route to forward the packet. This step ensures that the packet is sent along the most appropriate path available in the routing table. Identifying the physical egress interface is equally important because it specifies where the packet will exit the router towards its destination. Pushing traffic through the switch fabric is also an integral step in the forwarding process, allowing the packets to move through the hardware efficiently.

On the other hand, MAC address learning is part of the layer 2 Ethernet switching process rather than IP forwarding. It's mainly involved in building a table of MAC addresses that helps switches make decisions about forwarding frames at the data link layer. Thus, it does not contribute directly to the steps taken during the IP forwarding process, which operates at the layer 3 network level.