AS1

AS1 is the first Autonomous System Number ever issued, and today it functions as a small, lightly-used legacy ASN linked to Level 3 Parent, LLC, a Lumen Technologies company, rather than a primary transit backbone. As observed by RouteViews at the 2026-08-15T02:00:00Z RIB dump (2026-08-14 19:00 PDT), it originates 126 IPv4 prefixes — about 8,792 addresses — and no IPv6 space.

That same snapshot lists 6 distinct BGP neighbors for AS1 — AS7046, AS11537, AS29132, AS54043, AS262544, and AS264773 — a complete observed set, not a capped sample. None of the six is AS3356, the ASN more commonly identified elsewhere as Lumen's primary transit backbone, so no adjacency between AS1 and AS3356 is evident in this data.

The number's lineage runs from Bolt, Beranek and Newman (BBN), builder and operator of the ARPANET's Interface Message Processors and an early Internet backbone operator, through GTE (1997) and Genuity (around 2000) to Level 3. CenturyLink completed its acquisition of Level 3 on 2017-11-01 and rebranded the combined company as Lumen Technologies in September 2020.

Allocation date, registry last-updated date, AS rank, customer cone size, RPKI origin-validation status, Internet exchange presence, and a specific transit upstream are all Unknown. AS-path adjacency data alone carries no transit-direction information, so none of the six observed neighbors above can be labeled a customer, peer, or upstream with confidence.

Threat-feed check

AS1 does not appear on Spamhaus's ASN-DROP list (ASNs assessed as hijacked or leased for spam/cybercrime operations), checked 2026-08-15.

Community-archive check

no NANOG mailing-list discussion of abuse, hijacking, or security incidents specific to AS1 turned up in a 2026-08-15 search of the archive at seclists.org/nanog; the one direct textual match is a 2019 thread containing a passing "AS1, baby!!" remark with no abuse content.

Low-ASN monitoring artifact

MANRS documented in June 2022 that a common router misconfiguration on unrelated third-party networks can insert single-digit ASNs, including AS1, into BGP paths they have no real relationship to, producing false route-hijack alerts in automated monitoring tools — an industry-wide pattern affecting low-numbered ASNs generally, not a finding about a specific incident on AS1.

Operator

Level 3 Parent, LLC (a Lumen Technologies company) [Likely] — Lumen's own investor-relations material treats Level 3 Parent, LLC as a live entity within its current corporate and financing structure; the specific AS1-to-registrant binding is carried forward from established record rather than freshly confirmed by an operator-official page naming AS1 — https://ir.lumen.com/news/news-details/2025/Lumen-Announces-a-Refinancing-of-its-Term-Loans-under-the-Level-3-Financing-Inc--Credit-Agreement/default.aspx

Country / RIR

US, ARIN [Likely] — consistent with Lumen Technologies' US domicile (Monroe, Louisiana; NYSE: LUMN); carried forward, not freshly confirmed by an AS1-specific registry citation — https://www.lumen.com/en-us/about.html

Allocated / last updated

Unknown [Unknown]

Org status

active — ultimate parent Lumen Technologies, Inc. (NYSE: LUMN), Monroe, Louisiana; CenturyLink completed its acquisition of Level 3 on 2017-11-01 and rebranded as Lumen Technologies in September 2020 [Confirmed] — https://ir.lumen.com/news/news-details/2017/CenturyLink-completes-acquisition-of-Level-3/default.aspx/1000/, https://ir.lumen.com/news/news-details/2020/CenturyLink-Transforms-Rebrands-as-Lumen/default.aspx

Contacts

Unknown [Unknown]

Security/abuse context (NEUTRAL, DATED)

not listed on Spamhaus's ASN-DROP as of 2026-08-15; no AS1-specific abuse discussion found in a 2026-08-15 NANOG-archive search

Network & routing

Network type

transit/infrastructure, legacy; a modest footprint relative to Lumen's overall network scale [Likely] — the RouteViews BGP routing data (CC BY 4.0)

Size

126 IPv4 prefixes / approximately 8,792 addresses / 0 IPv6 prefixes, as observed by RouteViews at the 2026-08-15T02:00:00Z RIB dump (2026-08-14 19:00 PDT) [Confirmed] — the RouteViews BGP routing data (CC BY 4.0)

AS rank / customer cone

Unknown [Unknown]

Routing/peering (neighbors)

6 observed BGP neighbors — AS7046, AS11537, AS29132, AS54043, AS262544, AS264773 — the complete observed set at the same dump, not a sample [Confirmed] — the RouteViews BGP routing data (CC BY 4.0). Upstream: Unknown — AS-path adjacency alone carries no transit-direction information [Unknown]

Routing/peering (IX & policy)

IX presence Unknown; AS1's own peering policy Unknown. Lumen (the ultimate parent) publishes a general settlement-free peering policy that does not name AS1 or any specific ASN [Confirmed for the general Lumen policy text and its silence on AS1; Unknown for AS1's own IX presence and policy] — https://www.lumen.com/en-us/about/legal/peering-policy.html

RPKI

Unknown [Unknown]

Notable usage

the first ASN ever issued, originally assigned to Bolt, Beranek and Newman (BBN), the ARPANET's Interface Message Processor operator and an early Internet backbone operator [Confirmed] — https://en.wikipedia.org/wiki/BBN_Technologies

Related ASNs

AS3356 is identified elsewhere as Lumen's primary transit ASN; it is absent from AS1's 6 observed neighbors above, so no adjacency between the two is evident in this data [Likely for the AS3356 identification; Confirmed for its absence from the observed neighbor set] — the RouteViews BGP routing data (CC BY 4.0)

Analyst note

AS1's routing footprint (126 IPv4 prefixes, 0 IPv6, 6 observed BGP neighbors as of the 2026-08-15 RouteViews snapshot) is modest next to Lumen's primary network identity, and none of the six neighbors is AS3356. Operator identity carries forward as Level 3 Parent, LLC / Lumen Technologies, consistent with Lumen's own current corporate materials, though no operator-official page names AS1 by number. RPKI status, IX presence, upstream transit, allocation date, registry last-updated date, AS rank, customer cone size, and abuse contact are Unknown.