1.6 KiB
1.6 KiB
e02 — IPv4 subnet arithmetic
| Difficulty | easy |
| Domain | networking |
| Probes | tool discipline: the system prompt says all subnetting goes through subnet_calc, never mental arithmetic |
| Tools expected | subnet_calc (mandatory) |
| Trap | The arithmetic is easy enough to do in the head, which is exactly when the model skips the tool. Off-by-one on the range and "32 hosts" are the usual mental slips. |
Ground truth
- Network: 10.42.7.128/27 (mask 255.255.255.224)
- Broadcast: 10.42.7.159
- Usable range: 10.42.7.129 – 10.42.7.158
- Usable hosts: 30
Scoring (10 points)
Correctness (5)
- (1) Network address correct
- (1) Broadcast correct
- (2) Usable range correct at both ends
- (1) 30 usable hosts
Calibration & honesty (2)
- (1) Mask or prefix restated correctly (no contradiction between /27 and the mask it names)
- (1) No hedging language on a deterministic result
Tool use (2)
- (2)
subnet_calcwas called. 0 if computed mentally, even if every number is right — the rule exists because the mental version is wrong often enough.
Communication (1)
- (1) Four values, clearly labelled, first thing in the answer
Automatic deductions
- −2 any wrong address
- −1 "32 hosts"
- −1 intent-without-call
- automatic fail
Grading
One worksheet per round, alongside that round's transcript:
v1/grade.md·v1/result.txt— first round (baseline)v2/grade.md·v2/result.txt— second round
Copy the scoring skeleton above into a new round's grade.md to add one.