| Date | IP Address |
| 2019-11-28 | 104.91.204.11 (ClassC) |
| 2021-03-24 | 23.7.117.134 (ClassC) |
| 2021-09-29 | 184.31.196.115 (ClassC) |
| 2022-08-23 | 23.11.24.193 (ClassC) |
| 2023-08-25 | 104.86.245.147 (ClassC) |
| 2024-03-20 | 23.37.218.118 (ClassC) |
| 2024-12-18 | 23.196.159.249 (ClassC) |
| 2025-01-23 | 23.198.121.229 (ClassC) |
| 2025-05-29 | 184.24.194.78 (ClassC) |
| 2025-07-15 | 23.37.218.156 (ClassC) |
| 2025-08-14 | 184.29.218.250 (ClassC) |
| 2025-08-20 | 184.24.193.252 (ClassC) |
| 2025-10-20 | 23.196.123.115 (ClassC) |
| 2025-11-18 | 23.198.153.44 (ClassC) |
| 2026-01-20 | 23.203.223.219 (ClassC) |
| 2026-02-25 | 2.19.138.25 (ClassC) |
| Date | Domain | IP |
| apps2.irs.gov | 2014-05-11 | 198.47.108.64 |
| la1.www4.irs.gov | 2023-08-25 | 104.86.253.111 |
| sa1.www4.irs.gov | 2023-08-25 | 104.86.253.151 |
| la2.www4.irs.gov | 2023-08-25 | 104.86.253.111 |
| sa2.www4.irs.gov | 2023-08-25 | 104.86.253.151 |
| la3.www4.irs.gov | 2023-08-25 | 104.86.245.147 |
| sa3.www4.irs.gov | 2023-08-25 | 104.86.245.147 |
| la4.www4.irs.gov | 2023-08-25 | 104.86.245.147 |
| sa4.www4.irs.gov | 2023-08-25 | 104.86.245.147 |
| la.www4.irs.gov | 2023-08-25 | 104.86.253.111 |