AS281

AS281 is a legacy autonomous system number registered under ARIN to Level 3 Parent, LLC — the wholly owned subsidiary that holds the Level 3 Communications network assets now operated under the Lumen Technologies brand (NYSE: LUMN). The registry name is LVLT-281, ARIN handle AS281, with the organization entity LPL-141. The key triage point for AS281 is that it is effectively dormant: every routing source consulted (RIPEstat as-overview and routing-status, bgp.he.net, bgp.tools) agrees it announces zero IPv4 and zero IPv6 prefixes, is seen by 0 of 327 RIS peers (v4) and 0 of 324 (v6), and has 0 observed BGP neighbours. RIPEstat's routing history shows AS281 last had any visible routing presence around February 2003 — it announced prefix 199.92.105.0/24 as early as 2001-01-26 and was last seen with 198.114.157.0/24 on 2003-02-12 — meaning it has been routing-silent for more than twenty years. Level 3 / Lumen's active operational backbone runs under AS3356, a Tier 1 network ranked at or near the top of the global AS Cone; AS281 is an auxiliary/legacy number in the same portfolio. No notable public abuse signal was found as of June 2026: AS281 is not on the Spamhaus ASN-DROP list, and no NANOG, BGP-hijack, or route-leak reports referencing it were located — consistent with a clean, dormant ASN under a major established carrier. CAIDA AS Rank and customer-cone figures could not be retrieved (the CAIDA API returned HTTP 502), so those fields are recorded as Unknown rather than inferred.

Operator

Level 3 Parent, LLC (ARIN registry name LVLT-281; org entity LPL-141; operational brand Lumen Technologies) [Confirmed] — ARIN RDAP autnum/281, bgp.tools/as/281

Country / RIR

US, ARIN (block 1–1876, "Assigned by ARIN") [Confirmed] — ARIN RDAP, RIPEstat abuse-contact-finder (authoritative_rir: arin)

Allocated

2002-06-05 (ARIN RDAP autnum top-level registration event — a first-party RIR fact, NOT an IEEE date); last changed 2018-02-20 [Confirmed by A2 + A3] — ARIN RDAP autnum/281 top-level events[]

Org status

Level 3 Parent, LLC is a wholly owned subsidiary of Lumen Technologies, Inc. (NYSE: LUMN). Level 3 Communications, Inc. (formerly NYSE: LVLT) merged with CenturyLink (now Lumen) on 2017-11-01 and became a private LLC subsidiary

[Confirmed] — en.wikipedia.org/wiki/Level_3_Communications, SEC EDGAR subsidiary exhibit

Contacts

abuse@level3.com, +1-877-453-8353 (LAC56-ARIN); technical ipadmin@lumen.com (APL7-ARIN); RPKI-ROA rpki-roa@lumen.com (RPKIR-ARIN); registered address 100 CenturyLink Drive, Monroe, LA 71203 [Confirmed for abuse/RIR via RIPEstat + RDAP; Likely for full contact set via RDAP mirrors] — ARIN RDAP autnum/281, RIPEstat abuse-contact-finder

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-21 — not on Spamhaus ASN-DROP; no NANOG complaint threads, BGP-hijack reports, or route-leak disclosures referencing AS281. Several feeds (Cloudflare Radar, Cisco Talos, AbuseIPDB ASN view, CleanTalk) returned 403/404 and are recorded as Unknown, not as clearance [Confirmed for Spamhaus/NANOG; Unknown for blocked feeds] — spamhaus.org/drop/asndrop.txt, seclists.org/nanog

Network & routing

Network type

legacy/auxiliary ASN within the Level 3 / Lumen Tier 1 portfolio; currently inactive. Active backbone runs under AS3356 [Confirmed] — bgp.tools/as/281, bgp.tools/as/3356, en.wikipedia.org/wiki/Level_3_Communications

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes announced [Confirmed] — RIPEstat routing-status / bgp.he.net/AS281 (data as of 2026-06)

Routing/peering

NOT announced — 0 RIS peers seeing it (0/327 v4, 0/324 v6), 0 observed neighbours, 0 upstreams, 0 peers [Confirmed]. Historic routing: first seen 2001-01-26 (199.92.105.0/24), last seen 2003-02-12 (198.114.157.0/24) [Confirmed] — RIPEstat routing-status, bgp.he.net/AS281. Lumen's published settlement-free peering policy (revised 2021-09-09, peering@lumen.com) governs the broader Lumen network, principally AS3356, not AS281

[Confirmed for policy doc] — lumen.com peering-policy

RPKI

not assessable — AS281 announces no prefixes, so there are no ROAs to validate [Confirmed] — RIPEstat routing-status

Notable usage

AS281 (LVLT-281) is an auxiliary/legacy ASN in the Level 3 / Lumen portfolio with no observed active routing since ~2003; the primary operational ASN is AS3356 (top-ranked by AS Cone). Level 3 / Lumen operates one of the largest global IP backbones

[Confirmed] — en.wikipedia.org/wiki/Level_3_Communications, bgp.tools/as/3356

Related ASNs

AS3356 (Level 3 / Lumen's active operational backbone); AS1 (acquired from Genuity/BBN, 2003) [Confirmed for AS3356; Likely for AS1 association] — bgp.tools/as/3356, en.wikipedia.org/wiki/Level_3_Communications

Analyst note

Encountered as a dormant legacy ASN registered to a major Tier 1 carrier; WHOIS resolves to Level 3 Parent, LLC (Lumen), but live routing is under AS3356, not AS281. Clean, inactive ASN. CAIDA AS rank / cone unavailable (HTTP 502).