Question 300
A router selects an installed connected route for host 192.0.2.50 on Ethernet Gi0/0 but has no ARP entry for that host. What additional Layer 2 procedure is normally needed before it transmits a usable unicast Ethernet frame?
Explanation
Correct Answer
The routing table establishes that the host is on-link but does not inherently reveal its Ethernet hardware address. The router normally sends ARP to resolve the destination IPv4 address and then encapsulates the IP packet in a frame for that neighbor. A successful longest-prefix lookup and a known Layer 2 adjacency are separate requirements.
Incorrect Answers
A directly connected host does not need per-packet OSPF neighbor election. ARP is the on-link IPv4 address-to-MAC resolution protocol.
NAT is an optional address-translation feature at a policy boundary. It does not substitute for local Ethernet neighbor resolution on a connected network.
IP destination addressing is retained for the routed packet; Ethernet encapsulation uses the resolved neighbor MAC. A bridge forwarding table is not a replacement IPv4 destination.