{"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":"161.51.255.0/24","resource_type":"ipv4","page":"https://rirtracker.com/ip/161.51.255.0-161.51.255.255/","statistics_now":{"registry":"RIPE NCC","status":"assigned (dated 1992-05-27)"},"current_holder":{"rir":"RIPE NCC","org":"Kisters AG","how":"The RIPE NCC's latest statistics and the latest transfer record"},"rdap_snapshots":[],"transfers":[{"id":87398,"date":"2022-05-23T19:00:00Z","type":"RESOURCE_TRANSFER","source_rir":"ARIN","recipient_rir":"RIPE NCC","source_org":null,"recipient_org":"Kisters AG","range":"161.51.255.0/24","log":"RIPE NCC"},{"id":28147,"date":"2022-05-23T13:01:45Z","type":"RESOURCE_TRANSFER","source_rir":"ARIN","recipient_rir":"RIPE NCC","source_org":"KBR","recipient_org":"Kisters AG","range":"161.51.255.0/24","log":"ARIN"}],"events":[{"event_id":"a49c571bb072c918","registry":"ARIN","report_date":"2022-05-23","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"161.51.255.0/24","start":"161.51.255.0","end":"161.51.255.255","classification":"INTER_RIR_TRANSFER_OUT","classification_label":"Inter-RIR transfer out of ARIN","confidence":"CONFIRMED","source_rir":"ARIN","recipient_rir":"RIPE NCC","source_organization":"KBR","recipient_organization":"Kisters AG","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":"2026-10-14T00:19:02+00:00","page":"https://rirtracker.com/ip/161.51.255.0-161.51.255.255/#e-a49c571bb072c918","report_page":"https://rirtracker.com/arin/reports/2022-05-23/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/161.51.255.0-161.51.255.255.json","observed":"Transfer: KBR (ARIN) to Kisters AG (RIPE NCC)","piece_of":{"resource":"161.51.0.0/16","page":"https://rirtracker.com/ip/161.51.0.0-161.51.255.255/"},"same_transfer_as":"a4c98b8a5eb5a804","explanation":"ARIN's transfer log records a transfer from KBR (ARIN) to Kisters AG (RIPE NCC) on 2022-05-23 13:01 UTC: it left ARIN for the RIPE NCC. It is not a new allocation and is not offered to ARIN applicants.","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 2022-05-23 13:01 UTC, KBR (ARIN) to Kisters AG (RIPE NCC); resources moved: 161.51.255.0/24"},{"type":"delegated_before","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20220522.gz","retrieved_at":"2026-10-12T23:01:51+00:00","summary":"ARIN delegated statistics 2022-05-22 (produced 2022-05-22T13:00:14+00:00), before the report: allocated (dated 1992-05-27)"},{"type":"delegated_after","url":"https://ftp.arin.net/pub/stats/arin/archive/2022/delegated-arin-extended-20220524.gz","retrieved_at":"2026-10-12T23:01:55+00:00","summary":"ARIN delegated statistics 2022-05-24 (produced 2022-05-24T13:00:13+00:00), after the report: not listed"}]},{"event_id":"a4c98b8a5eb5a804","registry":"RIPE NCC","report_date":"2022-05-23","source":"transfers","raw_action":"TRANSFER","raw_line":null,"resource_type":"ipv4","resource":"161.51.255.0/24","start":"161.51.255.0","end":"161.51.255.255","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":"Kisters AG","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":"2026-10-13T23:49:05+00:00","page":"https://rirtracker.com/ip/161.51.255.0-161.51.255.255/#e-a4c98b8a5eb5a804","report_page":"https://rirtracker.com/ripe/reports/2022-05-23/","evidence_url":"https://rirtracker.com/api/v1/resources/ip/161.51.255.0-161.51.255.255.json","observed":"Transfer: (no name) (ARIN) to Kisters AG (RIPE NCC)","same_transfer_as":"a49c571bb072c918","explanation":"The RIPE NCC's transfer log records a transfer from an unnamed organization (ARIN) to Kisters AG (RIPE NCC) on 2022-05-23 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 2022-05-23 19:00 UTC, (no name) (ARIN) to Kisters AG (RIPE NCC); resources moved: 161.51.255.0/24"},{"type":"delegated_before","url":"https://ftp.ripe.net/pub/stats/ripencc/2022/delegated-ripencc-extended-20220522.bz2","retrieved_at":"2026-10-12T23:35:32+00:00","summary":"RIPE NCC delegated statistics 2022-05-22 (produced 2022-05-22T21:59:00+00:00), before the change: not listed"},{"type":"delegated_after","url":"https://ftp.ripe.net/pub/stats/ripencc/2022/delegated-ripencc-extended-20220523.bz2","retrieved_at":"2026-10-12T23:35:35+00:00","summary":"RIPE NCC delegated statistics 2022-05-23 (produced 2022-05-23T21:59:00+00:00), after the change: assigned (dated 1992-05-27)"}]}],"classification_history":{"a49c571bb072c918":[{"raw_change_id":565738,"classification_code":"INTER_RIR_TRANSFER_OUT","confidence":"CONFIRMED","classifier_version":"1.4.0","classified_at":"2026-10-14T00:19:02+00:00","current":1,"public_explanation":"ARIN's transfer log records a transfer from KBR (ARIN) to Kisters AG (RIPE NCC) on 2022-05-23 13:01 UTC: it left ARIN for the RIPE NCC. 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