Two computers C1 and C2 are configured as follows. C1 has IP address…
2006
Two computers C1 and C2 are configured as follows. C1 has IP address 203.197.2.53 and netmask 255.255.128.0. C2 has IP address 203.197.75.201 and netmask 255.255.192.0. which one of the following statements is true?
- A.
C1 and C2 both assume they are on the same network
- B.
C2 assumes C1 is on same network, but C1 assumes C2 is on a different network
- C.
C1 assumes C2 is on same network, but C2 assumes C1 is on a different network
- D.
C1 and C2 both assume they are on different networks.
Attempted by 123 students.
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Correct answer: C
Step 1: Convert masks to prefixes and find each host's network:
First computer: IP 203.197.2.53 with mask 255.255.128.0 = /17. Third-octet block size is 128, so its network is 203.197.0.0/17 (range 203.197.0.0–203.197.127.255).
Second computer: IP 203.197.75.201 with mask 255.255.192.0 = /18. Third-octet block size is 64, so its network is 203.197.64.0/18 (range 203.197.64.0–203.197.127.255).
Step 2: Each host applies its own mask to the other host's IP to decide if the other is local:
Applying the first computer's /17 mask to the second IP (203.197.75.201) yields 203.197.0.0, which matches the first computer's network. Therefore the first computer assumes the second is on the same network.
Applying the second computer's /18 mask to the first IP (203.197.2.53) yields 203.197.0.0, which does not match the second computer's network 203.197.64.0. Therefore the second computer assumes the first is on a different network.
Conclusion: The first computer assumes the second is on the same network, but the second computer assumes the first is on a different network.
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