{"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":"151.206.0.0/16","resource_type":"ipv4","page":"https://rirtracker.com/ip/151.206.0.0-151.206.255.255/","statistics_now":{"registry":"RIPE NCC","status":"allocated (dated 1991-09-25)"},"current_holder":{"rir":"RIPE NCC","org":"Microsoft Limited ","how":"The RIPE NCC's latest statistics and the latest transfer record"},"rdap_snapshots":[],"transfers":[{"id":89402,"date":"2022-09-01T19:00:00Z","type":"RESOURCE_TRANSFER","source_rir":"ARIN","recipient_rir":"RIPE NCC","source_org":null,"recipient_org":"Microsoft Limited","range":"151.206.0.0/16","log":"RIPE NCC"},{"id":29074,"date":"2022-09-01T13:08:29Z","type":"RESOURCE_TRANSFER","source_rir":"ARIN","recipient_rir":"RIPE NCC","source_org":"AECOM","recipient_org":"Microsoft Limited ","range":"151.206.0.0/16","log":"ARIN"},{"id":28444,"date":"2022-06-30T20:19:30Z","type":"MERGER_ACQUISITION","source_rir":"ARIN","recipient_rir":"ARIN","source_org":"Air & Water Technologies","recipient_org":"AECOM","range":"151.206.0.0/16","log":"ARIN"}],"events":[{"event_id":"705eebb35da5338a","registry":"ARIN","report_date":"2022-09-01","source":"statistics","raw_action":"NOT_IN_ARIN_ISSUED","raw_line":null,"resource_type":"ipv4","resource":"151.206.0.0/16","start":"151.206.0.0","end":"151.206.255.255","classification":"INTER_RIR_TRANSFER_OUT","classification_label":"Inter-RIR transfer out of ARIN","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"RIPE NCC","source_organization":"AECOM","recipient_organization":"Microsoft Limited ","inventory_effect":"Transferred out of ARIN administration; not offered to ARIN applicants","inventory_effect_code":"TRANSFER_OUT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:09:40+00:00","page":"https://rirtracker.com/ip/151.206.0.0-151.206.255.255/#e-705eebb35da5338a","report_page":"https://rirtracker.com/arin/reports/2022-09-01/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/151.206.0.0-151.206.255.255.json","observed":"151.206.0.0/16 allocated on 2022-09-01, not listed on 2022-09-02","same_transfer_as":"23cab417b00d3004","explanation":"ARIN's transfer log records a transfer from AECOM (ARIN) to Microsoft Limited  (RIPE NCC) on 2022-09-01 13:08 UTC: it left ARIN for the RIPE NCC. ARIN-Issued didn't list this change; it is not a new allocation and is not offered to ARIN applicants.","evidence":[{"type":"statistics_diff","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20220902.gz","retrieved_at":"2026-10-12T23:07:08+00:00","summary":"Not listed in ARIN-Issued; found by comparing ARIN's daily statistics: 151.206.0.0/16 allocated on 2022-09-01, not listed on 2022-09-02"},{"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 2022-09-01 13:08 UTC, AECOM (ARIN) to Microsoft Limited  (RIPE NCC); resources moved: 151.206.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20220831.gz","retrieved_at":"2026-10-12T23:07:03+00:00","summary":"ARIN delegated statistics 2022-08-31 (produced 2022-08-31T13:00:11+00:00), before the report: allocated (dated 1991-09-25)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20220902.gz","retrieved_at":"2026-10-12T23:07:08+00:00","summary":"ARIN delegated statistics 2022-09-02 (produced 2022-09-02T13:00:10+00:00), after the report: not listed"}]},{"event_id":"23cab417b00d3004","registry":"RIPE NCC","report_date":"2022-09-01","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"151.206.0.0/16","start":"151.206.0.0","end":"151.206.255.255","classification":"INTER_RIR_TRANSFER_IN","classification_label":"Inter-RIR transfer into the RIPE NCC","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"RIPE NCC","source_organization":null,"recipient_organization":"Microsoft Limited","inventory_effect":"Transferred into RIPE NCC administration; not a new issuance","inventory_effect_code":"TRANSFER_IN","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-13T23:49:12+00:00","page":"https://rirtracker.com/ip/151.206.0.0-151.206.255.255/#e-23cab417b00d3004","report_page":"https://rirtracker.com/ripe/reports/2022-09-01/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/151.206.0.0-151.206.255.255.json","observed":"Transfer: (no name) (ARIN) to Microsoft Limited (RIPE NCC)","same_transfer_as":"705eebb35da5338a","explanation":"The RIPE NCC's transfer log records a transfer from an unnamed organization (ARIN) to Microsoft Limited (RIPE NCC) on 2022-09-01 19:00 UTC: it came to the RIPE NCC from ARIN. It was already issued by another registry, so this is not a new issuance.","evidence":[{"type":"transfer","url":"https://ftp.ripe.net/pub/stats/ripencc/transfers/transfers_latest.json","retrieved_at":"2026-10-13T21:49:37+00:00","summary":"Transfer log: RESOURCE_TRANSFER on 2022-09-01 19:00 UTC, (no name) (ARIN) to Microsoft Limited (RIPE NCC); resources moved: 151.206.0.0/16"},{"type":"delegated_before","url":"https://ftp.ripe.net/pub/stats/ripencc/2022/delegated-ripencc-extended-20220831.bz2","retrieved_at":"2026-10-12T23:43:14+00:00","summary":"RIPE NCC delegated statistics 2022-08-31 (produced 2022-08-31T21:59:59+00:00), before the change: not listed"},{"type":"delegated_after","url":"https://ftp.ripe.net/pub/stats/ripencc/2022/delegated-ripencc-extended-20220901.bz2","retrieved_at":"2026-10-12T23:43:17+00:00","summary":"RIPE NCC delegated statistics 2022-09-01 (produced 2022-09-01T21:59:59+00:00), after the change: allocated (dated 1991-09-25)"}]},{"event_id":"85df5a5c96713a69","registry":"ARIN","report_date":"2022-06-30","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"151.206.0.0/16","start":"151.206.0.0","end":"151.206.255.255","classification":"MERGER_ACQUISITION","classification_label":"Merger/acquisition or reorganization","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"ARIN","source_organization":"Air & Water Technologies","recipient_organization":"AECOM","inventory_effect":"No effect on ARIN applicant inventory","inventory_effect_code":"NO_EFFECT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:03+00:00","page":"https://rirtracker.com/ip/151.206.0.0-151.206.255.255/#e-85df5a5c96713a69","report_page":"https://rirtracker.com/arin/reports/2022-06-30/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/151.206.0.0-151.206.255.255.json","observed":"Merger/acquisition: Air & Water Technologies (ARIN) to AECOM (ARIN)","explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Air & Water Technologies (ARIN) to AECOM (ARIN) on 2022-06-30 20:19 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 2022-06-30 20:19 UTC, Air & Water Technologies (ARIN) to AECOM (ARIN); resources moved: 151.206.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20220629.gz","retrieved_at":"2026-10-12T23:03:40+00:00","summary":"ARIN delegated statistics 2022-06-29 (produced 2022-06-29T13:00:08+00:00), before the report: allocated (dated 1991-09-25)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20220701.gz","retrieved_at":"2026-10-12T23:03:55+00:00","summary":"ARIN delegated statistics 2022-07-01 (produced 2022-07-01T13:00:09+00:00), after the report: allocated (dated 1991-09-25)"}]}],"classification_history":{"705eebb35da5338a":[{"raw_change_id":432807,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.3.0","classified_at":"2026-10-13T05:53:20+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from AECOM (ARIN) to Microsoft Limited  (RIPE NCC) on 2022-09-01 13:08 UTC: it left ARIN for the RIPE NCC. ARIN-Issued didn't list this change; it is not a new allocation and is not offered to ARIN applicants."},{"raw_change_id":432807,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.3.1","classified_at":"2026-10-13T08:20:53+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from AECOM (ARIN) to Microsoft Limited  (RIPE NCC) on 2022-09-01 13:08 UTC: it left ARIN for the RIPE NCC. ARIN-Issued didn't list this change; it is not a new allocation and is not offered to ARIN applicants."},{"raw_change_id":432807,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.3.2","classified_at":"2026-10-13T15:04:49+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from AECOM (ARIN) to Microsoft Limited  (RIPE NCC) on 2022-09-01 13:08 UTC: it left ARIN for the RIPE NCC. ARIN-Issued didn't list this change; it is not a new allocation and is not offered to ARIN applicants."},{"raw_change_id":432807,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-14T00:09:40+00:00","current":1,"public_explanation":"ARIN's transfer log records a transfer from AECOM (ARIN) to Microsoft Limited  (RIPE NCC) on 2022-09-01 13:08 UTC: it left ARIN for the RIPE NCC. ARIN-Issued didn't list this change; it is not a new allocation and is not offered to ARIN applicants."}],"23cab417b00d3004":[{"raw_change_id":89744,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.3.0","classified_at":"2026-10-13T02:58:22+00:00","current":0,"public_explanation":"The RIPE NCC's transfer log records a transfer from an unnamed organization (ARIN) to Microsoft Limited (RIPE NCC) on 2022-09-01 19:00 UTC: it came to the RIPE NCC from ARIN. It was already issued by another registry, so this is not a new issuance."},{"raw_change_id":89744,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.3.1","classified_at":"2026-10-13T08:04:00+00:00","current":0,"public_explanation":"The RIPE NCC's transfer log records a transfer from an unnamed organization (ARIN) to Microsoft Limited (RIPE NCC) on 2022-09-01 19:00 UTC: it came to the RIPE NCC from ARIN. It was already issued by another registry, so this is not a new issuance."},{"raw_change_id":89744,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.3.2","classified_at":"2026-10-13T14:46:25+00:00","current":0,"public_explanation":"The RIPE NCC's transfer log records a transfer from an unnamed organization (ARIN) to Microsoft Limited (RIPE NCC) on 2022-09-01 19:00 UTC: it came to the RIPE NCC from ARIN. It was already issued by another registry, so this is not a new issuance."},{"raw_change_id":89744,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-13T23:49:12+00:00","current":1,"public_explanation":"The RIPE NCC's transfer log records a transfer from an unnamed organization (ARIN) to Microsoft Limited (RIPE NCC) on 2022-09-01 19:00 UTC: it came to the RIPE NCC from ARIN. It was already issued by another registry, so this is not a new issuance."}],"85df5a5c96713a69":[{"raw_change_id":565923,"classification_code":"MERGER_ACQUISITION","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:03+00:00","current":1,"public_explanation":"ARIN's transfer log records a merger, acquisition or reorganization from Air & Water Technologies (ARIN) to AECOM (ARIN) on 2022-06-30 20:19 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":"not listed"}}