Autonomous system
AS15157 NORWORLD - NORTHWESTERN CORPORATION
Unclassified ARIN
Summary
NorthWestern Corporation
business infrastructure
A carrier netname that writes the address in hexadecimal, with a counter on the end.
What it's used for
- A utility company's network. Two IPv4 prefixes announced from the United States, no IPv6, and three observed BGP neighbours.
Notable
- One block carries the netname
SPRINT-CE6BEB5, where the six hexadecimal characters after the carrier's name decode to the first three octets of the/24it labels, and the final character is a counter. - The other carries the bare product name
SPRINTLINK, with no address and no counter at all. - Both blocks are registered to the holder, written entirely in capitals, while the AS handle uses an abbreviation that appears nowhere else in the record.
- Six addresses were queried for reverse DNS and none returned a name.
Interesting
- This is the second holder in this range whose blocks carry hexadecimal addresses inside a carrier's netname, and it settles what the scheme is: the same carrier applies it across unrelated customers, six characters for the network and a trailing digit to distinguish assignments from the same range.
- Nothing marks the string as hexadecimal, so it reads as noise unless you already know the convention. A netname that encodes an address without saying so is worse than one that spells it out, because nobody thinks to decode it.
- Two blocks, three upstreams, no reverse names, and an AS handle matching neither the company nor its netnames. The routing is the only field that describes this network accurately.
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.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-11-11, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 2 prefixes · 768 addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 2 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS15157- Registry name
- NORWORLD
- Registrant
- NORTHWESTERN CORPORATION
- Abuse contact
- Sean.Cleverly@northwestern.com
- Registered
- 2000-03-27
- Last changed
- 2012-03-02
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 3 with no ROA
- ROAs
- 0 authorising AS15157
- ASPA
- no ASPA record
- IRR
- 100% registered · 3 of 3 announcements
- Route objects
- 13 naming AS15157
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: 453 networks and 1,846 prefixes, as published 2026-11-12. 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