AS251

AS251 is a legacy 16-bit autonomous system number held in the RIPE NCC registry as a personal/hobbyist allocation rather than a corporate network. The authoritative RIPE RDAP autnum object lists no organisation entity; instead it carries two individual maintainers — DKLIMEK-MNT (Denis Klimek) and HIBLER-MNT (Florian Hibler, address Enzianstrasse 3, 82494 Krün, DE) — across the administrative, technical, and registrant roles, with RIPEstat's as-overview reporting the holder string "AS251 - IDDQD-AS." The key triage point is that AS251 is effectively dormant today: RIPEstat routing-status and CAIDA AS Rank agree it announces zero IPv4 and zero IPv6 prefixes, has zero visible peers, upstreams, providers, and customers, and is seen by 0 of 327 RIS peers (v4) and 0 of 324 (v6). It was last visible in the global routing table on 2020-10-28 (prefix 193.34.48.0/24, which bgp.he.net flags as a bogon); RIPEstat first observed it routing on 2004-11-02 (195.245.114.0/23). Its CAIDA AS rank of 79,459 sits near the bottom of the global ranking, with a singleton customer cone (1 ASN, 0 prefixes, 0 addresses) and degree 0 across all relationship types. The autnum top-level registration event is dated 2002-08-21, last changed 2025-04-23. No notable public abuse signal was found as of June 2026 — not in Spamhaus DROP/ASN-DROP, AbuseIPDB, or NANOG archives — consistent with a clean, inactive personal ASN. Two research angles asserted alternative holders ("FIQ-AS" and "Kaia Global Networks Ltd."); both conflict with the first-party RIPE RDAP record and could not be corroborated, so the RDAP/RIPEstat holder is treated as authoritative.

Operator

Denis Klimek (individual); co-maintainer Florian Hibler — no organisation entity in the RIPE record; holder string "IDDQD-AS" [Confirmed] — RIPE RDAP (https://rdap.db.ripe.net/autnum/251), RIPEstat as-overview (https://stat.ripe.net/data/as-overview/data.json?resource=AS251)

Country / RIR

DE / EU (inferred from contact addresses — Denis Klimek, Germany; Florian Hibler, Krün, DE), RIPE NCC [Likely for country; Confirmed for RIR] — RIPE RDAP (https://rdap.db.ripe.net/autnum/251), RIPEstat abuse-contact-finder (authoritative_rir: ripe)

Allocated

2002-08-21 (RIPE RDAP autnum top-level registration event, 2002-08-21T16:06:01Z — a first-party registry fact, NOT an IEEE date); last changed 2025-04-23 [Confirmed] — RIPE RDAP autnum top-level events (https://rdap.db.ripe.net/autnum/251)

Org status

individual/personal ASN — no corporate org object in the RIPE record; maintainers DKLIMEK-MNT and HIBLER-MNT. Two angles asserted alternative holders ("FIQ-AS"; "Kaia Global Networks Ltd.") but neither is supported by the first-party RDAP and both are treated as unverified [Confirmed for no-org; conflicting third-party claims noted] — RIPE RDAP (https://rdap.db.ripe.net/autnum/251)

Contacts

no abuse contact returned by RIPEstat abuse-contact-finder; admin/tech contacts Denis Klimek (DK8381-RIPE) and Florian Hibler (FH-RIPE) [Confirmed] — RIPEstat abuse-contact-finder, RIPE RDAP (https://rdap.db.ripe.net/autnum/251)

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-20 — not in Spamhaus DROP/ASN-DROP, AbuseIPDB, or NANOG archives; a non-routing ASN presents no operational attack surface

Network & routing

Network type

personal/hobbyist legacy ASN; dormant — no commercial ISP, hosting, or enterprise profile [Likely] — bgp.he.net (https://bgp.he.net/AS251), bgp.tools (https://bgp.tools/as/251)

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses [Confirmed] — RIPEstat routing-status (https://stat.ripe.net/data/routing-status/data.json?resource=AS251), CAIDA AS Rank (https://api.caida.org/as-rank/v1/asns/251)

Routing/peering

NOT announced — 0 RIS peers seeing it (0/327 v4, 0/324 v6); CAIDA degree total 0 (customer 0, peer 0, provider 0); last seen routing 2020-10-28, first seen 2004-11-02 [Confirmed]. Sole historical observed peer AS15943 (wilhelm.tel GmbH, DE)

[Likely] — RIPEstat routing-status, bgp.he.net (https://bgp.he.net/AS251)

RPKI

not assessable — AS251 announces no prefixes, so there are no ROAs to validate [Confirmed] — bgp.he.net (https://bgp.he.net/AS251)

Notable usage

member of several European IXP AS-SETs per bgp.tools (e.g. DE-CIX/AMS-IX/PLIX-related sets), consistent with co-maintainer Florian Hibler's documented IXP/ISP career; no routes announced since 2020 [Likely] — bgp.tools (https://bgp.tools/as/251), labs.ripe.net/author/fhibler

PeeringDB / website

no PeeringDB entry (404 on /asn/251); no website listed in RIPE WHOIS, PeeringDB, bgp.he.net, or bgp.tools [Confirmed] — peeringdb.com/asn/251, bgp.he.net (https://bgp.he.net/AS251), bgp.tools (https://bgp.tools/as/251)

Analyst note

Encountered as a dormant legacy personal ASN under RIPE; holder is an individual (IDDQD-AS), not a company. Conflicting third-party holder claims ("FIQ-AS", "Kaia Global Networks") were rejected in favour of the first-party RIPE RDAP record. Clean, inactive ASN.