| Date | IP Address |
| 2018-11-27 | 54.88.170.149 (ClassC) |
| 2019-11-24 | 18.214.125.126 (ClassC) |
| 2022-08-04 | 52.23.43.146 (ClassC) |
| 2024-08-07 | 54.82.51.61 (ClassC) |
| 2024-09-27 | 100.25.236.193 (ClassC) |
| 2025-04-16 | 34.232.216.58 (ClassC) |
| 2025-06-03 | 35.174.212.140 (ClassC) |
| 2025-06-23 | 3.233.91.168 (ClassC) |
| 2025-09-06 | 44.195.219.148 (ClassC) |
| 2025-09-13 | 34.199.84.233 (ClassC) |
| 2025-11-19 | 100.24.200.149 (ClassC) |
| Date | Domain | IP |
| curiousgeorge-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| hmhco-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| api-consumer-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| cliffsnotes-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| subscriptions-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| api-subscriptions-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| admin-subscriptions-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| gomathacademy-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| web-delivery-v1.int.webnp.hmhco.com | 2025-08-04 | 18.235.151.113 |
| hmhco-v2.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| hmhco-v1.cert.webnp.hmhco.com | 2025-10-30 | 54.166.166.198 |
| gomathacademy-v1.cert.webnp.hmhco.com | 2025-08-10 | 45.60.11.203 |
| web-delivery-v1.cert.webnp.hmhco.com | 2024-06-03 | 44.207.80.202 |
| cliffsnotes-v1.dev.webnp.hmhco.com | 2024-08-09 | 44.209.124.240 |
| gomathacademy-v1.dev.webnp.hmhco.com | 2025-04-11 | 34.231.11.210 |
| web-delivery-int.dev.webnp.hmhco.com | 2025-08-10 | 54.167.13.139 |