{"classifier_version":"1.4.0","documentation":"https://rirtracker.com/api/","disclaimer":"This site independently analyzes publicly available Internet number-resource records. It is not affiliated with or endorsed by ARIN, the RIPE NCC, APNIC, LACNIC, AFRINIC, the Number Resource Organization (NRO), or any other Regional Internet Registry. Classifications and hold-expiration dates are evidence-based interpretations and do not constitute confirmation that a resource is available for issuance or transfer.","resource":"155.40.0.0/16","resource_type":"ipv4","page":"https://rirtracker.com/ip/155.40.0.0-155.40.255.255/","statistics_now":{"registry":"ARIN","status":"allocated (dated 2023-05-08)"},"current_holder":{"rir":"ARIN","org":"Amazon.com, Inc.","how":"ARIN's latest statistics and the latest transfer record"},"rdap_snapshots":[],"transfers":[{"id":31871,"date":"2023-05-08T16:09:36Z","type":"RESOURCE_TRANSFER","source_rir":"ARIN","recipient_rir":"ARIN","source_org":"Cengage Learning, Inc.","recipient_org":"Amazon.com, Inc.","range":"155.40.0.0/16","log":"ARIN"},{"id":29453,"date":"2022-10-21T17:37:38Z","type":"MERGER_ACQUISITION","source_rir":"ARIN","recipient_rir":"ARIN","source_org":"Information Access Center","recipient_org":"Cengage Learning Inc","range":"155.40.0.0/16","log":"ARIN"}],"events":[{"event_id":"3ef9be867b7a1194","registry":"ARIN","report_date":"2023-05-08","source":"arin_issued","raw_action":"ADD","raw_line":"Add 155.40.0.0-155.40.255.255","resource_type":"ipv4","resource":"155.40.0.0/16","start":"155.40.0.0","end":"155.40.255.255","classification":"INTRA_RIR_TRANSFER","classification_label":"Intra-ARIN transfer","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"ARIN","source_organization":"Cengage Learning, Inc.","recipient_organization":"Amazon.com, Inc.","inventory_effect":"No effect on ARIN applicant inventory","inventory_effect_code":"NO_EFFECT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-13T23:53:42+00:00","page":"https://rirtracker.com/ip/155.40.0.0-155.40.255.255/#e-3ef9be867b7a1194","report_page":"https://rirtracker.com/arin/reports/2023-05-08/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/155.40.0.0-155.40.255.255.json","explanation":"ARIN's transfer log records a transfer from Cengage Learning, Inc. (ARIN) to Amazon.com, Inc. (ARIN) on 2023-05-08 16:09 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN.","evidence":[{"type":"arin_issued","url":"https://lists.arin.net/pipermail/arin-issued/2023-May/005260.html","retrieved_at":"2026-10-12T18:42:10+00:00","summary":"ARIN-Issued report for 2023-05-08: \"Add 155.40.0.0-155.40.255.255\""},{"type":"transfer","url":"https://ftp.arin.net/pub/stats/arin/transfers/transfers_latest.json","retrieved_at":"2026-10-13T13:57:20+00:00","summary":"Transfer log: RESOURCE_TRANSFER on 2023-05-08 16:09 UTC, Cengage Learning, Inc. (ARIN) to Amazon.com, Inc. (ARIN); resources moved: 155.40.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2023/delegated-arin-extended-20230507.gz","retrieved_at":"2026-10-12T23:20:15+00:00","summary":"ARIN delegated statistics 2023-05-07 (produced 2023-05-07T13:00:10+00:00), before the report: allocated (dated 1995-04-24)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2023/delegated-arin-extended-20230509.gz","retrieved_at":"2026-10-12T23:20:20+00:00","summary":"ARIN delegated statistics 2023-05-09 (produced 2023-05-09T13:00:11+00:00), after the report: allocated (dated 2023-05-08)"}]},{"event_id":"f2161dc9dbfc641f","registry":"ARIN","report_date":"2022-10-21","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"155.40.0.0/16","start":"155.40.0.0","end":"155.40.255.255","classification":"MERGER_ACQUISITION","classification_label":"Merger/acquisition or reorganization","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"ARIN","source_organization":"Information Access Center","recipient_organization":"Cengage Learning Inc","inventory_effect":"No effect on ARIN applicant inventory","inventory_effect_code":"NO_EFFECT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:04+00:00","page":"https://rirtracker.com/ip/155.40.0.0-155.40.255.255/#e-f2161dc9dbfc641f","report_page":"https://rirtracker.com/arin/reports/2022-10-21/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/155.40.0.0-155.40.255.255.json","observed":"Merger/acquisition: Information Access Center (ARIN) to Cengage Learning Inc (ARIN)","explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Information Access Center (ARIN) to Cengage Learning Inc (ARIN) on 2022-10-21 17:37 UTC. The registration changed hands; it is not a new allocation from ARIN. ARIN-Issued and ARIN's statistics don't show this change; only the transfer log records it.","evidence":[{"type":"transfer","url":"https://ftp.arin.net/pub/stats/arin/transfers/transfers_latest.json","retrieved_at":"2026-10-13T13:57:20+00:00","summary":"Transfer log: MERGER_ACQUISITION on 2022-10-21 17:37 UTC, Information Access Center (ARIN) to Cengage Learning Inc (ARIN); resources moved: 155.40.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20221020.gz","retrieved_at":"2026-10-12T23:09:34+00:00","summary":"ARIN delegated statistics 2022-10-20 (produced 2022-10-20T13:00:11+00:00), before the report: allocated (dated 1995-04-24)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20221022.gz","retrieved_at":"2026-10-12T23:09:49+00:00","summary":"ARIN delegated statistics 2022-10-22 (produced 2022-10-22T13:00:10+00:00), after the report: allocated (dated 1995-04-24)"}]}],"classification_history":{"3ef9be867b7a1194":[{"raw_change_id":181562,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.3.0","classified_at":"2026-10-13T03:59:05+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Cengage Learning, Inc. (ARIN) to Amazon.com, Inc. (ARIN) on 2023-05-08 16:09 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."},{"raw_change_id":181562,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.3.1","classified_at":"2026-10-13T08:07:27+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Cengage Learning, Inc. (ARIN) to Amazon.com, Inc. (ARIN) on 2023-05-08 16:09 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."},{"raw_change_id":181562,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.3.2","classified_at":"2026-10-13T14:50:17+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Cengage Learning, Inc. (ARIN) to Amazon.com, Inc. (ARIN) on 2023-05-08 16:09 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."},{"raw_change_id":181562,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-13T23:53:42+00:00","current":1,"public_explanation":"ARIN's transfer log records a transfer from Cengage Learning, Inc. (ARIN) to Amazon.com, Inc. (ARIN) on 2023-05-08 16:09 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."}],"f2161dc9dbfc641f":[{"raw_change_id":566550,"classification_code":"MERGER_ACQUISITION","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:04+00:00","current":1,"public_explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Information Access Center (ARIN) to Cengage Learning Inc (ARIN) on 2022-10-21 17:37 UTC. The registration changed hands; it is not a new allocation from ARIN. ARIN-Issued and ARIN's statistics don't show this change; only the transfer log records it."}]},"arin_statistics_now":{"status":"allocated (dated 2023-05-08)"}}