{"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":"144.121.0.0/16","resource_type":"ipv4","page":"https://rirtracker.com/ip/144.121.0.0-144.121.255.255/","statistics_now":{"registry":"ARIN","status":"allocated (dated 2016-04-29)"},"current_holder":{"rir":"ARIN","org":"Zayo Bandwidth","how":"ARIN's latest statistics and the latest transfer record"},"rdap_snapshots":[],"transfers":[{"id":44122,"date":"2026-06-01T16:06:28Z","type":"MERGER_ACQUISITION","source_rir":"ARIN","recipient_rir":"ARIN","source_org":"Crown Castle Fiber LLC","recipient_org":"Zayo Bandwidth","range":"144.121.0.0/16","log":"ARIN"},{"id":34629,"date":"2024-02-29T20:25:53Z","type":"MERGER_ACQUISITION","source_rir":"ARIN","recipient_rir":"ARIN","source_org":"Lightower Fiber Networks I, LLC","recipient_org":"Crown Castle Fiber LLC","range":"144.121.0.0/16","log":"ARIN"},{"id":6874,"date":"2016-04-29T19:45:08Z","type":"RESOURCE_TRANSFER","source_rir":"ARIN","recipient_rir":"ARIN","source_org":"Weyerhaeuser Company","recipient_org":"Lightower Fiber Networks I, LLC","range":"144.121.0.0/16","log":"ARIN"}],"events":[{"event_id":"979e8aafbcb28fff","registry":"ARIN","report_date":"2026-06-01","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"144.121.0.0/16","start":"144.121.0.0","end":"144.121.255.255","classification":"MERGER_ACQUISITION","classification_label":"Merger/acquisition or reorganization","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"ARIN","source_organization":"Crown Castle Fiber LLC","recipient_organization":"Zayo Bandwidth","inventory_effect":"No effect on ARIN applicant inventory","inventory_effect_code":"NO_EFFECT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:28+00:00","page":"https://rirtracker.com/ip/144.121.0.0-144.121.255.255/#e-979e8aafbcb28fff","report_page":"https://rirtracker.com/arin/reports/2026-06-01/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/144.121.0.0-144.121.255.255.json","observed":"Merger/acquisition: Crown Castle Fiber LLC (ARIN) to Zayo Bandwidth (ARIN)","explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Crown Castle Fiber LLC (ARIN) to Zayo Bandwidth (ARIN) on 2026-06-01 16:06 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 2026-06-01 16:06 UTC, Crown Castle Fiber LLC (ARIN) to Zayo Bandwidth (ARIN); resources moved: 144.121.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/delegated-arin-extended-20260531","retrieved_at":"2026-10-09T19:02:06+00:00","summary":"ARIN delegated statistics 2026-05-31 (produced 2026-05-31T13:00:19+00:00), before the report: allocated (dated 2016-04-29)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/delegated-arin-extended-20260602","retrieved_at":"2026-10-09T19:02:12+00:00","summary":"ARIN delegated statistics 2026-06-02 (produced 2026-06-02T13:00:19+00:00), after the report: allocated (dated 2016-04-29)"}]},{"event_id":"478ea71d3d33afb9","registry":"ARIN","report_date":"2024-02-29","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"144.121.0.0/16","start":"144.121.0.0","end":"144.121.255.255","classification":"MERGER_ACQUISITION","classification_label":"Merger/acquisition or reorganization","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"ARIN","source_organization":"Lightower Fiber Networks I, LLC","recipient_organization":"Crown Castle Fiber LLC","inventory_effect":"No effect on ARIN applicant inventory","inventory_effect_code":"NO_EFFECT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:13+00:00","page":"https://rirtracker.com/ip/144.121.0.0-144.121.255.255/#e-478ea71d3d33afb9","report_page":"https://rirtracker.com/arin/reports/2024-02-29/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/144.121.0.0-144.121.255.255.json","observed":"Merger/acquisition: Lightower Fiber Networks I, LLC (ARIN) to Crown Castle Fiber LLC (ARIN)","explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Lightower Fiber Networks I, LLC (ARIN) to Crown Castle Fiber LLC (ARIN) on 2024-02-29 20:25 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 2024-02-29 20:25 UTC, Lightower Fiber Networks I, LLC (ARIN) to Crown Castle Fiber LLC (ARIN); resources moved: 144.121.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2024/delegated-arin-extended-20240228.gz","retrieved_at":"2026-10-12T23:35:58+00:00","summary":"ARIN delegated statistics 2024-02-28 (produced 2024-02-28T14:00:43+00:00), before the report: allocated (dated 2016-04-29)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2024/delegated-arin-extended-20240301.gz","retrieved_at":"2026-10-12T23:36:03+00:00","summary":"ARIN delegated statistics 2024-03-01 (produced 2024-03-01T14:00:43+00:00), after the report: allocated (dated 2016-04-29)"}]},{"event_id":"f35976f08b5834c2","registry":"ARIN","report_date":"2016-04-29","source":"arin_issued","raw_action":"ADD","raw_line":"Add 144.121.0.0-144.121.255.255","resource_type":"ipv4","resource":"144.121.0.0/16","start":"144.121.0.0","end":"144.121.255.255","classification":"INTRA_RIR_TRANSFER","classification_label":"Intra-ARIN transfer","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"ARIN","source_organization":"Weyerhaeuser Company","recipient_organization":"Lightower Fiber Networks I, LLC","inventory_effect":"No effect on ARIN applicant inventory","inventory_effect_code":"NO_EFFECT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-13T23:51:34+00:00","page":"https://rirtracker.com/ip/144.121.0.0-144.121.255.255/#e-f35976f08b5834c2","report_page":"https://rirtracker.com/arin/reports/2016-04-29/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/144.121.0.0-144.121.255.255.json","explanation":"ARIN's transfer log records a transfer from Weyerhaeuser Company (ARIN) to Lightower Fiber Networks I, LLC (ARIN) on 2016-04-29 19:45 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/2016-April/002696.html","retrieved_at":"2026-10-12T18:39:10+00:00","summary":"ARIN-Issued report for 2016-04-29: \"Add 144.121.0.0-144.121.255.255\""},{"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 2016-04-29 19:45 UTC, Weyerhaeuser Company (ARIN) to Lightower Fiber Networks I, LLC (ARIN); resources moved: 144.121.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2016/delegated-arin-extended-20160428.gz","retrieved_at":"2026-10-12T21:09:32+00:00","summary":"ARIN delegated statistics 2016-04-28 (produced 2016-04-28T05:04:39+00:00), before the report: assigned (dated 1990-12-03)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2016/delegated-arin-extended-20160430.gz","retrieved_at":"2026-10-12T21:09:44+00:00","summary":"ARIN delegated statistics 2016-04-30 (produced 2016-04-30T05:04:53+00:00), after the report: allocated (dated 2016-04-29)"}]}],"classification_history":{"979e8aafbcb28fff":[{"raw_change_id":576251,"classification_code":"MERGER_ACQUISITION","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:28+00:00","current":1,"public_explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Crown Castle Fiber LLC (ARIN) to Zayo Bandwidth (ARIN) on 2026-06-01 16:06 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."}],"478ea71d3d33afb9":[{"raw_change_id":570280,"classification_code":"MERGER_ACQUISITION","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:13+00:00","current":1,"public_explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Lightower Fiber Networks I, LLC (ARIN) to Crown Castle Fiber LLC (ARIN) on 2024-02-29 20:25 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."}],"f35976f08b5834c2":[{"raw_change_id":141498,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.3.0","classified_at":"2026-10-13T03:35:13+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Weyerhaeuser Company (ARIN) to Lightower Fiber Networks I, LLC (ARIN) on 2016-04-29 19:45 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."},{"raw_change_id":141498,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.3.1","classified_at":"2026-10-13T08:05:50+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Weyerhaeuser Company (ARIN) to Lightower Fiber Networks I, LLC (ARIN) on 2016-04-29 19:45 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."},{"raw_change_id":141498,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.3.2","classified_at":"2026-10-13T14:48:28+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Weyerhaeuser Company (ARIN) to Lightower Fiber Networks I, LLC (ARIN) on 2016-04-29 19:45 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."},{"raw_change_id":141498,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-13T23:51:34+00:00","current":1,"public_explanation":"ARIN's transfer log records a transfer from Weyerhaeuser Company (ARIN) to Lightower Fiber Networks I, LLC (ARIN) on 2016-04-29 19:45 UTC. ARIN-Issued lists it as \"Add\" because the registration changed hands; it is not a new allocation from ARIN."}]},"arin_statistics_now":{"status":"allocated (dated 2016-04-29)"}}