| Date | IP Address |
| 2025-01-09 | 89.191.86.55 (ClassC) |
| Date | Domain | IP |
| backoffice.reisen.check24.de | 2025-01-01 | 89.191.89.90 |
| tracking.reisen.check24.de | 2024-12-27 | 89.191.91.185 |
| tcms.reisen.check24.de | 2025-01-09 | 89.191.86.55 |
| www.reisen.check24.de | 2024-09-22 | 89.191.67.180 |