{"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":"143.171.0.0/16","resource_type":"ipv4","page":"https://rirtracker.com/ip/143.171.0.0-143.171.255.255/","statistics_now":{"registry":"ARIN","status":"allocated (dated 2024-12-03)"},"current_holder":{"rir":"ARIN","org":"AMAZO-4","how":"ARIN's latest statistics and the latest transfer record"},"rdap_snapshots":[],"transfers":[{"id":129812,"date":"2024-12-04T02:26:06Z","type":"RESOURCE_TRANSFER","source_rir":"APNIC","recipient_rir":"ARIN","source_org":"Net One Systems Co.Ltd.","recipient_org":"AMAZO-4","range":"143.171.0.0/16","log":"APNIC"},{"id":37408,"date":"2024-12-03T19:53:18Z","type":"RESOURCE_TRANSFER","source_rir":"APNIC","recipient_rir":"ARIN","source_org":"Net One Systems Co. Ltd.","recipient_org":"Amazon.com, Inc.","range":"143.171.0.0/16","log":"ARIN"}],"events":[{"event_id":"69a5a5a2421d5eb1","registry":"APNIC","report_date":"2024-12-04","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"143.171.0.0/16","start":"143.171.0.0","end":"143.171.255.255","classification":"INTER_RIR_TRANSFER_OUT","classification_label":"Inter-RIR transfer out of APNIC","confidence":"CONFIRMED","source_rir":"APNIC","recipient_rir":"ARIN","source_organization":"Net One Systems Co.Ltd.","recipient_organization":"AMAZO-4","inventory_effect":"Transferred out of APNIC administration; not offered to APNIC applicants","inventory_effect_code":"TRANSFER_OUT","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-13T23:46:52+00:00","page":"https://rirtracker.com/ip/143.171.0.0-143.171.255.255/#e-69a5a5a2421d5eb1","report_page":"https://rirtracker.com/apnic/reports/2024-12-04/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/143.171.0.0-143.171.255.255.json","observed":"Transfer: Net One Systems Co.Ltd. (APNIC) to AMAZO-4 (ARIN)","same_transfer_as":"0754b6972a5b31b7","explanation":"APNIC's transfer log records a transfer from Net One Systems Co.Ltd. (APNIC) to AMAZO-4 (ARIN) on 2024-12-04 02:26 UTC: it left APNIC for ARIN. It is not a new allocation and is not offered to APNIC applicants.","evidence":[{"type":"transfer","url":"https://ftp.apnic.net/stats/apnic/transfers/transfers_latest.json","retrieved_at":"2026-10-13T18:17:16+00:00","summary":"Transfer log: RESOURCE_TRANSFER on 2024-12-04 02:26 UTC, Net One Systems Co.Ltd. (APNIC) to AMAZO-4 (ARIN); resources moved: 143.171.0.0/16, 143.221.0.0/16, 143.253.0.0/16"},{"type":"delegated_before","url":"https://ftp.apnic.net/stats/apnic/2024/delegated-apnic-extended-20241204.gz","retrieved_at":"2026-10-13T01:24:27+00:00","summary":"APNIC delegated statistics 2024-12-04, before the change: allocated (dated 2011-02-17)"},{"type":"delegated_after","url":"https://ftp.apnic.net/stats/apnic/2024/delegated-apnic-extended-20241205.gz","retrieved_at":"2026-10-13T01:24:31+00:00","summary":"APNIC delegated statistics 2024-12-05, after the change: not listed"}]},{"event_id":"0754b6972a5b31b7","registry":"ARIN","report_date":"2024-12-03","source":"arin_issued","raw_action":"ADD","raw_line":"Add 143.171.0.0-143.171.255.255","resource_type":"ipv4","resource":"143.171.0.0/16","start":"143.171.0.0","end":"143.171.255.255","classification":"INTER_RIR_TRANSFER_IN","classification_label":"Inter-RIR transfer into ARIN","confidence":"CONFIRMED","source_rir":"APNIC","recipient_rir":"ARIN","source_organization":"Net One Systems Co. Ltd.","recipient_organization":"Amazon.com, Inc.","inventory_effect":"Transferred into ARIN administration; not a new issuance","inventory_effect_code":"TRANSFER_IN","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-13T23:54:16+00:00","page":"https://rirtracker.com/ip/143.171.0.0-143.171.255.255/#e-0754b6972a5b31b7","report_page":"https://rirtracker.com/arin/reports/2024-12-03/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/143.171.0.0-143.171.255.255.json","same_transfer_as":"69a5a5a2421d5eb1","explanation":"ARIN's transfer log records a transfer from Net One Systems Co. Ltd. (APNIC) to Amazon.com, Inc. (ARIN) on 2024-12-03 19:53 UTC: it came to ARIN from APNIC. It was already issued by another registry, so this is not a new issuance.","evidence":[{"type":"arin_issued","url":"https://lists.arin.net/pipermail/arin-issued/2024-December/005834.html","retrieved_at":"2026-10-12T18:42:50+00:00","summary":"ARIN-Issued report for 2024-12-03: \"Add 143.171.0.0-143.171.255.255\""},{"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 2024-12-03 19:53 UTC, Net One Systems Co. Ltd. (APNIC) to Amazon.com, Inc. (ARIN); resources moved: 143.171.0.0/16"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2024/delegated-arin-extended-20241202.gz","retrieved_at":"2026-10-12T23:50:57+00:00","summary":"ARIN delegated statistics 2024-12-02 (produced 2024-12-02T14:01:06+00:00), before the report: not listed"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2024/delegated-arin-extended-20241204.gz","retrieved_at":"2026-10-12T23:51:02+00:00","summary":"ARIN delegated statistics 2024-12-04 (produced 2024-12-04T14:01:07+00:00), after the report: allocated (dated 2024-12-03)"}]},{"event_id":"9bccd684e67829be","registry":"APNIC","report_date":"2024-05-10","source":"statistics","raw_action":"ADDED","raw_line":null,"resource_type":"ipv4","resource":"143.171.0.0/16","start":"143.171.0.0","end":"143.171.255.255","classification":"UNRESOLVED","classification_label":"Unresolved change","confidence":"OBSERVED_ONLY","source_rir":null,"recipient_rir":null,"source_organization":null,"recipient_organization":null,"inventory_effect":"Inventory effect unknown","inventory_effect_code":"UNKNOWN","provisional":false,"classifier_version":"1.4.0","classified_at":"2026-10-14T00:17:01+00:00","page":"https://rirtracker.com/ip/143.171.0.0-143.171.255.255/#e-9bccd684e67829be","report_page":"https://rirtracker.com/apnic/reports/2024-05-10/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/143.171.0.0-143.171.255.255.json","observed":"143.171.0.0/16 reserved on 2024-05-10, allocated on 2024-05-11","explanation":"No transfer record matches. APNIC's statistics show it reserved on 2024-05-10 and allocated (dated 2011-02-17) on 2024-05-11. The new registration isn't dated near that day, so the tracker can't tell whether this is a new issuance.","evidence":[{"type":"statistics_diff","url":"https://ftp.apnic.net/stats/apnic/2024/delegated-apnic-extended-20240511.gz","retrieved_at":"2026-10-13T01:08:41+00:00","summary":"Found by comparing APNIC's daily statistics: 143.171.0.0/16 reserved on 2024-05-10, allocated on 2024-05-11"},{"type":"delegated_before","url":"https://ftp.apnic.net/stats/apnic/2024/delegated-apnic-extended-20240510.gz","retrieved_at":"2026-10-13T01:08:38+00:00","summary":"APNIC delegated statistics 2024-05-10, before the change: reserved"},{"type":"delegated_after","url":"https://ftp.apnic.net/stats/apnic/2024/delegated-apnic-extended-20240511.gz","retrieved_at":"2026-10-13T01:08:41+00:00","summary":"APNIC delegated statistics 2024-05-11, after the change: allocated (dated 2011-02-17)"}]},{"event_id":"2e2ee08d3c89d741","registry":"APNIC","report_date":"2011-02-17","source":"statistics","raw_action":"REMOVED","raw_line":null,"resource_type":"ipv4","resource":"143.171.0.0/16","start":"143.171.0.0","end":"143.171.255.255","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":"2026-10-13T23:57:05+00:00","page":"https://rirtracker.com/ip/143.171.0.0-143.171.255.255/#e-2e2ee08d3c89d741","report_page":"https://rirtracker.com/apnic/reports/2011-02-17/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/143.171.0.0-143.171.255.255.json","observed":"143.171.0.0/16 allocated on 2011-02-17, not listed on 2011-02-18","explanation":"Removed from active registration. The tracker found it by comparing APNIC's daily statistics. APNIC's statistics show it allocated (dated 1990-09-26) on 2011-02-17 and not listed on 2011-02-18. 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-20110218.gz","retrieved_at":"2026-10-12T19:33:52+00:00","summary":"Found by comparing APNIC's daily statistics: 143.171.0.0/16 allocated on 2011-02-17, not listed on 2011-02-18"},{"type":"delegated_before","url":"https://ftp.apnic.net/stats/apnic/2011/delegated-apnic-extended-20110217.gz","retrieved_at":"2026-10-12T19:33:49+00:00","summary":"APNIC delegated statistics 2011-02-17, before the change: allocated (dated 1990-09-26)"},{"type":"delegated_after","url":"https://ftp.apnic.net/stats/apnic/2011/delegated-apnic-extended-20110218.gz","retrieved_at":"2026-10-12T19:33:52+00:00","summary":"APNIC delegated statistics 2011-02-18, after the change: not listed"}]}],"classification_history":{"69a5a5a2421d5eb1":[{"raw_change_id":41621,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.3.0","classified_at":"2026-10-13T02:38:30+00:00","current":0,"public_explanation":"APNIC's transfer log records a transfer from Net One Systems Co.Ltd. (APNIC) to AMAZO-4 (ARIN) on 2024-12-04 02:26 UTC: it left APNIC for ARIN. It is not a new allocation and is not offered to APNIC applicants."},{"raw_change_id":41621,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.3.1","classified_at":"2026-10-13T08:02:05+00:00","current":0,"public_explanation":"APNIC's transfer log records a transfer from Net One Systems Co.Ltd. (APNIC) to AMAZO-4 (ARIN) on 2024-12-04 02:26 UTC: it left APNIC for ARIN. It is not a new allocation and is not offered to APNIC applicants."},{"raw_change_id":41621,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.3.2","classified_at":"2026-10-13T14:44:16+00:00","current":0,"public_explanation":"APNIC's transfer log records a transfer from Net One Systems Co.Ltd. (APNIC) to AMAZO-4 (ARIN) on 2024-12-04 02:26 UTC: it left APNIC for ARIN. It is not a new allocation and is not offered to APNIC applicants."},{"raw_change_id":41621,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-13T23:46:52+00:00","current":1,"public_explanation":"APNIC's transfer log records a transfer from Net One Systems Co.Ltd. (APNIC) to AMAZO-4 (ARIN) on 2024-12-04 02:26 UTC: it left APNIC for ARIN. It is not a new allocation and is not offered to APNIC applicants."}],"0754b6972a5b31b7":[{"raw_change_id":190641,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.3.0","classified_at":"2026-10-13T04:04:09+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Net One Systems Co. Ltd. (APNIC) to Amazon.com, Inc. (ARIN) on 2024-12-03 19:53 UTC: it came to ARIN from APNIC. It was already issued by another registry, so this is not a new issuance."},{"raw_change_id":190641,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.3.1","classified_at":"2026-10-13T08:07:52+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Net One Systems Co. Ltd. (APNIC) to Amazon.com, Inc. (ARIN) on 2024-12-03 19:53 UTC: it came to ARIN from APNIC. It was already issued by another registry, so this is not a new issuance."},{"raw_change_id":190641,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.3.2","classified_at":"2026-10-13T14:50:45+00:00","current":0,"public_explanation":"ARIN's transfer log records a transfer from Net One Systems Co. Ltd. (APNIC) to Amazon.com, Inc. (ARIN) on 2024-12-03 19:53 UTC: it came to ARIN from APNIC. It was already issued by another registry, so this is not a new issuance."},{"raw_change_id":190641,"classification_code":"INTER_RIR_TRANSFER_IN","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-13T23:54:16+00:00","current":1,"public_explanation":"ARIN's transfer log records a transfer from Net One Systems Co. Ltd. (APNIC) to Amazon.com, Inc. (ARIN) on 2024-12-03 19:53 UTC: it came to ARIN from APNIC. It was already issued by another registry, so this is not a new issuance."}],"9bccd684e67829be":[{"raw_change_id":527903,"classification_code":"UNRESOLVED","confidence":"OBSERVED_ONLY","classifier_version":"1.3.0","classified_at":"2026-10-13T06:37:47+00:00","current":0,"public_explanation":"No transfer record matches. APNIC's statistics show it reserved on 2024-05-10 and allocated (dated 2011-02-17) on 2024-05-11. The new registration isn't dated near that day, so the tracker can't tell whether this is a new issuance."},{"raw_change_id":527903,"classification_code":"UNRESOLVED","confidence":"OBSERVED_ONLY","classifier_version":"1.3.1","classified_at":"2026-10-13T08:26:47+00:00","current":0,"public_explanation":"No transfer record matches. APNIC's statistics show it reserved on 2024-05-10 and allocated (dated 2011-02-17) on 2024-05-11. The new registration isn't dated near that day, so the tracker can't tell whether this is a new issuance."},{"raw_change_id":527903,"classification_code":"UNRESOLVED","confidence":"OBSERVED_ONLY","classifier_version":"1.3.2","classified_at":"2026-10-13T15:11:09+00:00","current":0,"public_explanation":"No transfer record matches. APNIC's statistics show it reserved on 2024-05-10 and allocated (dated 2011-02-17) on 2024-05-11. The new registration isn't dated near that day, so the tracker can't tell whether this is a new issuance."},{"raw_change_id":527903,"classification_code":"UNRESOLVED","confidence":"OBSERVED_ONLY","classifier_version":"1.4.0","classified_at":"2026-10-14T00:17:01+00:00","current":1,"public_explanation":"No transfer record matches. APNIC's statistics show it reserved on 2024-05-10 and allocated (dated 2011-02-17) on 2024-05-11. The new registration isn't dated near that day, so the tracker can't tell whether this is a new issuance."}],"2e2ee08d3c89d741":[{"raw_change_id":240085,"classification_code":"REMOVED_REASON_UNKNOWN","confidence":"OBSERVED_ONLY","classifier_version":"1.3.0","classified_at":"2026-10-13T04:25:34+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 1990-09-26) on 2011-02-17 and not listed on 2011-02-18. 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":240085,"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 1990-09-26) on 2011-02-17 and not listed on 2011-02-18. 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":240085,"classification_code":"REMOVED_REASON_UNKNOWN","confidence":"OBSERVED_ONLY","classifier_version":"1.3.2","classified_at":"2026-10-13T14:53:22+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 1990-09-26) on 2011-02-17 and not listed on 2011-02-18. 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":240085,"classification_code":"REMOVED_REASON_UNKNOWN","confidence":"OBSERVED_ONLY","classifier_version":"1.4.0","classified_at":"2026-10-13T23:57:05+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 1990-09-26) on 2011-02-17 and not listed on 2011-02-18. 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":"allocated (dated 2024-12-03)"}}