ITPEC FE Subject A April 2025 Question 23
ITPEC FE Subject A April 2025 — Question 23 of 60
Router Packet Forwarding — routers use the destination IP address to forward packets.
A router operates at Layer 3 (Network layer) of the OSI model and uses the destination IP address in the packet header to look up the next hop in its routing table.
- •Layer 3 devices (routers) → use IP addresses for forwarding decisions
- •Layer 2 devices (switches) → use MAC addresses for forwarding decisions
Why not others:
- (b) Destination MAC address — used by switches (Layer 2), not routers
- (c) Source IP address — indicates origin, not where to forward
- (d) Source MAC address — Layer 2 info about origin, irrelevant for routing
Key rule: Router = IP address, Switch = MAC address.
AI-generated — may contain errors
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