{"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":"151.158.0.0/16","resource_type":"ipv4","page":"https://rirtracker.com/ip/151.158.0.0-151.158.255.255/","statistics_now":{"registry":"APNIC","status":"allocated (84 records, dated 2026-01-09 to 2026-03-04), assigned (57 records, dated 2026-01-13 to 2026-03-03)"},"current_holder":{"rir":"APNIC","org":null,"how":"APNIC's latest statistics"},"rdap_snapshots":[],"transfers":[],"events":[{"event_id":"71e1e4a62bd1180e","registry":"APNIC","report_date":"2021-08-25","source":"statistics","raw_action":"RELEASED","raw_line":null,"resource_type":"ipv4","resource":"151.158.0.0/16","start":"151.158.0.0","end":"151.158.255.255","classification":"HOLD_RELEASED","classification_label":"Released from hold (APNIC lists it as 'available')","confidence":"STRONG_INFERENCE","source_rir":null,"recipient_rir":null,"source_organization":null,"recipient_organization":null,"inventory_effect":"APNIC's statistics now list it as 'available'; reissue not confirmed","inventory_effect_code":"RELEASED","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:12:46+00:00","page":"https://rirtracker.com/ip/151.158.0.0-151.158.255.255/#e-71e1e4a62bd1180e","report_page":"https://rirtracker.com/apnic/reports/2021-08-25/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/151.158.0.0-151.158.255.255.json","observed":"151.158.0.0/16 reserved on 2021-08-25, available on 2021-08-26","explanation":"APNIC's statistics show it reserved on 2021-08-25 and available on 2021-08-26. APNIC moved it from its reserved (held) records to the status it calls 'available'. The tracker saw it removed from registration on 2011-02-24, 3835 days earlier. That is APNIC's own label: whether and when it is reissued is not confirmed.","evidence":[{"type":"statistics_diff","url":"https://ftp.apnic.net/stats/apnic/2021/delegated-apnic-extended-20210826.gz","retrieved_at":"2026-10-12T23:52:04+00:00","summary":"Found by comparing APNIC's daily statistics: 151.158.0.0/16 reserved on 2021-08-25, available on 2021-08-26"},{"type":"delegated_before","url":"https://ftp.apnic.net/stats/apnic/2021/delegated-apnic-extended-20210825.gz","retrieved_at":"2026-10-12T23:52:01+00:00","summary":"APNIC delegated statistics 2021-08-25, before the change: reserved"},{"type":"delegated_after","url":"https://ftp.apnic.net/stats/apnic/2021/delegated-apnic-extended-20210826.gz","retrieved_at":"2026-10-12T23:52:04+00:00","summary":"APNIC delegated statistics 2021-08-26, after the change: available"}]},{"event_id":"1f81c405349b59e5","registry":"APNIC","report_date":"2011-02-24","source":"statistics","raw_action":"REMOVED","raw_line":null,"resource_type":"ipv4","resource":"151.158.0.0/16","start":"151.158.0.0","end":"151.158.255.255","classification":"REMOVED_REASON_UNKNOWN","classification_label":"Removed (return, revocation or reclamation not publicly distinguishable)","confidence":"OBSERVED_ONLY","source_rir":null,"recipient_rir":null,"source_organization":null,"recipient_organization":null,"inventory_effect":"Possible future reissue candidate after hold","inventory_effect_code":"HOLD_CANDIDATE","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-13T23:57:06+00:00","page":"https://rirtracker.com/ip/151.158.0.0-151.158.255.255/#e-1f81c405349b59e5","report_page":"https://rirtracker.com/apnic/reports/2011-02-24/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/151.158.0.0-151.158.255.255.json","observed":"151.158.0.0/16 allocated on 2011-02-24, not listed on 2011-02-25","explanation":"Removed from active registration. The tracker found it by comparing APNIC's daily statistics. APNIC's statistics show it allocated (dated 1991-07-30) on 2011-02-24 and not listed on 2011-02-25. Being gone from APNIC's statistics entirely can also mean it moved to another registry. Public sources do not distinguish a voluntary return, revocation, or reclamation. APNIC publishes no hold period, and its statistics show a steady one (a year) only for removals from 2014-07-01 on; this one came earlier, so the tracker gives no estimate. This does not confirm availability.","evidence":[{"type":"statistics_diff","url":"https://ftp.apnic.net/stats/apnic/2011/delegated-apnic-extended-20110225.gz","retrieved_at":"2026-10-12T19:34:14+00:00","summary":"Found by comparing APNIC's daily statistics: 151.158.0.0/16 allocated on 2011-02-24, not listed on 2011-02-25"},{"type":"delegated_before","url":"https://ftp.apnic.net/stats/apnic/2011/delegated-apnic-extended-20110224.gz","retrieved_at":"2026-10-12T19:34:11+00:00","summary":"APNIC delegated statistics 2011-02-24, before the change: allocated (dated 1991-07-30)"},{"type":"delegated_after","url":"https://ftp.apnic.net/stats/apnic/2011/delegated-apnic-extended-20110225.gz","retrieved_at":"2026-10-12T19:34:14+00:00","summary":"APNIC delegated statistics 2011-02-25, after the change: not listed"}]}],"classification_history":{"71e1e4a62bd1180e":[{"raw_change_id":474106,"classification_code":"HOLD_RELEASED","confidence":"STRONG_INFERENCE","classifier_version":"1.3.0","classified_at":"2026-10-13T06:11:25+00:00","current":0,"public_explanation":"APNIC's statistics show it reserved on 2021-08-25 and available on 2021-08-26. APNIC moved it from its reserved (held) records to the status it calls 'available'. The tracker saw it removed from registration on 2011-02-24, 3835 days earlier. That is APNIC's own label: whether and when it is reissued is not confirmed."},{"raw_change_id":474106,"classification_code":"HOLD_RELEASED","confidence":"STRONG_INFERENCE","classifier_version":"1.3.1","classified_at":"2026-10-13T08:23:21+00:00","current":0,"public_explanation":"APNIC's statistics show it reserved on 2021-08-25 and available on 2021-08-26. APNIC moved it from its reserved (held) records to the status it calls 'available'. The tracker saw it removed from registration on 2011-02-24, 3835 days earlier. That is APNIC's own label: whether and when it is reissued is not confirmed."},{"raw_change_id":474106,"classification_code":"HOLD_RELEASED","confidence":"STRONG_INFERENCE","classifier_version":"1.3.2","classified_at":"2026-10-13T15:07:28+00:00","current":0,"public_explanation":"APNIC's statistics show it reserved on 2021-08-25 and available on 2021-08-26. APNIC moved it from its reserved (held) records to the status it calls 'available'. The tracker saw it removed from registration on 2011-02-24, 3835 days earlier. That is APNIC's own label: whether and when it is reissued is not confirmed."},{"raw_change_id":474106,"classification_code":"HOLD_RELEASED","confidence":"STRONG_INFERENCE","classifier_version":"1.4.0","classified_at":"2026-10-14T00:12:46+00:00","current":1,"public_explanation":"APNIC's statistics show it reserved on 2021-08-25 and available on 2021-08-26. APNIC moved it from its reserved (held) records to the status it calls 'available'. The tracker saw it removed from registration on 2011-02-24, 3835 days earlier. That is APNIC's own label: whether and when it is reissued is not confirmed."}],"1f81c405349b59e5":[{"raw_change_id":240285,"classification_code":"REMOVED_REASON_UNKNOWN","confidence":"OBSERVED_ONLY","classifier_version":"1.3.0","classified_at":"2026-10-13T04:25:43+00:00","current":0,"public_explanation":"Removed from active registration. The tracker found it by comparing APNIC's daily statistics. APNIC's statistics show it allocated (dated 1991-07-30) on 2011-02-24 and not listed on 2011-02-25. Being gone from APNIC's statistics entirely can also mean it moved to another registry. Public sources do not distinguish a voluntary return, revocation, or reclamation. APNIC publishes no fixed period for which it holds returned IPv4 space before reissuing it, so the tracker gives no estimate. This does not confirm availability."},{"raw_change_id":240285,"classification_code":"REMOVED_REASON_UNKNOWN","confidence":"OBSERVED_ONLY","classifier_version":"1.3.1","classified_at":"2026-10-13T08:10:16+00:00","current":0,"public_explanation":"Removed from active registration. The tracker found it by comparing APNIC's daily statistics. APNIC's statistics show it allocated (dated 1991-07-30) on 2011-02-24 and not listed on 2011-02-25. Being gone from APNIC's statistics entirely can also mean it moved to another registry. Public sources do not distinguish a voluntary return, revocation, or reclamation. APNIC publishes no fixed period for which it holds returned IPv4 space before reissuing it, so the tracker gives no estimate. This does not confirm availability."},{"raw_change_id":240285,"classification_code":"REMOVED_REASON_UNKNOWN","confidence":"OBSERVED_ONLY","classifier_version":"1.3.2","classified_at":"2026-10-13T14:53:23+00:00","current":0,"public_explanation":"Removed from active registration. The tracker found it by comparing APNIC's daily statistics. APNIC's statistics show it allocated (dated 1991-07-30) on 2011-02-24 and not listed on 2011-02-25. Being gone from APNIC's statistics entirely can also mean it moved to another registry. Public sources do not distinguish a voluntary return, revocation, or reclamation. APNIC publishes no fixed period for which it holds returned IPv4 space before reissuing it, so the tracker gives no estimate. This does not confirm availability."},{"raw_change_id":240285,"classification_code":"REMOVED_REASON_UNKNOWN","confidence":"OBSERVED_ONLY","classifier_version":"1.4.0","classified_at":"2026-10-13T23:57:06+00:00","current":1,"public_explanation":"Removed from active registration. The tracker found it by comparing APNIC's daily statistics. APNIC's statistics show it allocated (dated 1991-07-30) on 2011-02-24 and not listed on 2011-02-25. Being gone from APNIC's statistics entirely can also mean it moved to another registry. Public sources do not distinguish a voluntary return, revocation, or reclamation. APNIC publishes no hold period, and its statistics show a steady one (a year) only for removals from 2014-07-01 on; this one came earlier, so the tracker gives no estimate. This does not confirm availability."}]},"arin_statistics_now":{"status":"not listed"}}