| Date | IP Address |
| 2023-11-01 | 13.78.64.171 (ClassC) |
| 2024-04-13 | 133.167.7.4 (ClassC) |
| 2024-08-10 | 133.167.25.3 (ClassC) |
| 2024-11-25 | 153.121.2.1 (ClassC) |
| 2024-12-06 | 133.167.7.3 (ClassC) |
| 2024-12-17 | 153.121.2.3 (ClassC) |
| 2025-04-23 | 133.167.7.2 (ClassC) |
| 2025-06-22 | 133.167.25.1 (ClassC) |
| 2025-07-08 | 133.167.25.2 (ClassC) |
| 2025-08-10 | 153.121.1.3 (ClassC) |
| Date | Domain | IP |
| syllabus.kosen-k.go.jp | 2024-04-13 | 104.41.179.0 |
| www.kosen-k.go.jp | 2023-11-01 | 13.78.64.171 |