Router 3
Router 3 receives the data packet and strips off the Network Interface layer information revealing the destination IP address.
Router 3 determines that the traffic is destined for network 192.168.4.0 and checks its routing table where it shows that one of Router 3’s interfaces is connected to network 192.168.4.0.
Router 3 must now determine which host on the network has the IP address 192.168.4.22.
Router 3 checks its ARP table to get a MAC address mapping for the client. If no mapping exists, Router 3 issues an ARP Request on network 192.168.4.0 to get a mapping.
Once the router has the correct MAC to IP mapping, it repackages the Network Interface layer using the MAC address of the Host B.