{"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":"141.251.0.0/16","resource_type":"ipv4","page":"https://rirtracker.com/ip/141.251.0.0-141.251.255.255/","statistics_now":{"registry":"ARIN","status":"allocated (dated 2011-06-22)"},"current_holder":{"rir":"ARIN","org":"Microsoft Corp","how":"ARIN's latest statistics and the latest transfer record"},"rdap_snapshots":[],"transfers":[{"id":5350,"date":"2011-06-22T19:57:00Z","type":"RESOURCE_TRANSFER","source_rir":"ARIN","recipient_rir":"ARIN","source_org":"SynOptics Communications, Inc","recipient_org":"Microsoft Corp","range":"141.251.0.0/16","log":"ARIN"}],"events":[{"event_id":"12d80509f7e26bd7","registry":"ARIN","report_date":"2011-06-22","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"141.251.0.0/16","start":"141.251.0.0","end":"141.251.255.255","classification":"INTRA_RIR_TRANSFER","classification_label":"Intra-ARIN transfer","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"ARIN","source_organization":"SynOptics Communications, Inc","recipient_organization":"Microsoft Corp","inventory_effect":"No effect on ARIN applicant inventory","inventory_effect_code":"NO_EFFECT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:18:22+00:00","page":"https://rirtracker.com/ip/141.251.0.0-141.251.255.255/#e-12d80509f7e26bd7","report_page":"https://rirtracker.com/arin/reports/2011-06-22/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/141.251.0.0-141.251.255.255.json","observed":"Transfer: SynOptics Communications, Inc (ARIN) to Microsoft Corp (ARIN)","explanation":"ARIN's transfer log records a transfer from SynOptics Communications, Inc (ARIN) to Microsoft Corp (ARIN) on 2011-06-22 19:57 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: RESOURCE_TRANSFER on 2011-06-22 19:57 UTC, SynOptics Communications, Inc (ARIN) to Microsoft Corp (ARIN); resources moved: 141.251.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2011/delegated-arin-20110621.gz","retrieved_at":"2026-10-12T19:21:40+00:00","summary":"ARIN delegated statistics 2011-06-21, before the report: assigned (dated 1990-08-22)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2011/delegated-arin-20110623.gz","retrieved_at":"2026-10-12T19:21:44+00:00","summary":"ARIN delegated statistics 2011-06-23, after the report: assigned (dated 1990-08-22)"}]}],"classification_history":{"12d80509f7e26bd7":[{"raw_change_id":549160,"classification_code":"INTRA_RIR_TRANSFER","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-14T00:18:22+00:00","current":1,"public_explanation":"ARIN's transfer log records a transfer from SynOptics Communications, Inc (ARIN) to Microsoft Corp (ARIN) on 2011-06-22 19:57 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 2011-06-22)"}}