A packet with the destination IP address 145.36.109.70 arrives at a router…
2025
A packet with the destination IP address 145.36.109.70 arrives at a router whose routing table is shown. Which interface will the packet be forwarded to?
- A.
E3
- B.
E1
- C.
E2
- D.
E5
Attempted by 137 students.
Show answer & explanation
Correct answer: A
Final answer: E3
Reasoning: Use longest-prefix match (the most specific route). Check which table entries include 145.36.109.70.
145.36.255.0/24: covers 145.36.255.0–145.36.255.255 — does not include 145.36.109.70.
145.36.64.0/18: mask 255.255.192.0, covers 145.36.64.0–145.36.127.255 — this range includes 145.36.109.70.
145.36.128.0/17: covers 145.36.128.0–145.36.255.255 — does not include 145.36.109.70.
145.36.0.0/16: covers 145.36.0.0–145.36.255.255 — includes the address but is less specific than the /18 entry.
Conclusion: The most specific matching route is 145.36.64.0/18, so the router forwards the packet to E3.
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