asn.dev

Autonomous system

AS21896 ALLIANT-ENERGY

Unclassified ARIN

IPv4 addresses 4.10K 7 prefixes
IPv6 prefixes 0 counted as prefixes, not addresses
Countries 1 mostly US
Exchanges 0 recorded by PCH
Upstreams 4 0 downstream
Flagged prefixes 0 none

Summary

Alliant Energy

United States of America · AI-generated

utility corporate business infrastructure

ALLIANT-ENERGY is operated by Alliant Energy, a major electric and natural gas utility serving the Midwest United States.

What it's used for

  • The address space is registered under netnames NETBLK-ALI1 and NETBLK-ALI2, both assigned to Alliant Energy, indicating a corporate internal network for utility operations.
  • The AS announces 4096 IPv4 addresses across 7 prefixes with only 4 observed neighbours, a ratio consistent with a private corporate estate rather than a public transit or access provider.

Notable

  • All registrants in the RDAP data match the announcer, listing Alliant Energy for every prefix.
  • The address inventory is finely subdivided into two distinct blocks (198.7.44.0/22 and 207.71.128.0/23 series), suggesting site-by-site segmentation typical of large industrial or utility infrastructure.

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

Full topology · Graph

Internet exchanges

No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.

Transit providers

4 upstream, 0 downstream and 4 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS393238ImOn Communications, LLC204
AS4181TDS TELECOM132
AS40264Charter Communications LLC104
AS3356Level 3 Parent, LLC68

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-16, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.

Address space

Summary

Shape and geography

IPv4 7 prefixes · 4.10K addresses IPv6 0 prefixes

CountryNamePrefixes
USUnited States of America7

Registry

Allocation record

ARIN · via Atlas (registry + RDAP)
Registry
ARIN
Handle
AS21896
Registry name
ALLIANT-ENERGY
Registrant
Alliant Energy
Abuse contact
DL_IT_Data_Network-ALI@alliantenergy.com
Registered
2009-01-08
Last changed
2012-03-02
Allocation
assigned

Routing security

RPKI and IRR

Full detail
RPKI
0% valid · 0 valid, 8 with no ROA
ROAs
0 authorising AS21896
ASPA
no ASPA record
IRR
100% registered · 8 of 8 announcements
Route objects
41 naming AS21896

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: 442 networks and 1,783 prefixes, as published 2026-10-17. 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

Cross-check