Autonomous system
AS3909 CENTURYLINK-LEGACY-QWEST-VDOC - CenturyLink Communications, LLC
Unclassified ARIN
Summary
CenturyLink Communications, LLC (Lumen)
isp legacy
A CenturyLink Communications, LLC autonomous system (CENTURYLINK-LEGACY-QWEST-VDOC) inherited from Qwest, now part of Lumen Technologies.
What it's used for
- Announcing a small set of prefixes — roughly 7,000 IPv4 addresses — behind Lumen's main backbone, AS209, which is its only upstream.
- Functionally a stub: a handful of routed blocks rather than a transit network in its own right.
Notable
- Despite the carrier name, this ASN is not a backbone. Lumen's actual transit business runs on AS209 and AS3356; AS3909 carries a narrow slice of legacy Qwest routing.
- The
VDOCelement of the handle is not documented publicly and should not be read as identifying any particular customer or division.
Interesting
- Lumen holds a long tail of these legacy Qwest and CenturyLink ASNs, absorbed through decades of mergers. The naming convention —
CENTURYLINK-LEGACY-*— is the company labelling its own acquisition history in the registry.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Transit providers
1 upstream, 0 downstream and 1 adjacent networks observed; most-used upstreams first.
| AS | Network | Paths seen |
|---|---|---|
| AS209 | CenturyLink Communications, LLC | 300 |
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-31, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 4 prefixes · 6.91K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 4 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS3909- Registry name
- CENTURYLINK-LEGACY-QWEST-VDOC
- Registrant
- CenturyLink Communications, LLC
- Abuse contact
- abuse@aup.lumen.com
- Registered
- 1996-10-01
- Last changed
- 2018-10-04
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 5 with no ROA
- ROAs
- 0 authorising AS3909
- ASPA
- no ASPA record
- IRR
- 0% registered · 0 of 5 announcements
- Route objects
- 0 naming AS3909
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 447 networks and 1,843 prefixes, as published 2026-11-01. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere