asn.dev

Autonomous system

AS19121 BLATTNER-HOLDING-COMPANY

Unclassified ARIN

IPv4 addresses 256 1 prefixes
IPv6 prefixes 0 counted as prefixes, not addresses
Countries 1 mostly US
Exchanges 0 recorded by PCH
Upstreams 1 0 downstream
Flagged prefixes 0 none

Summary

Blattner Company

United States of America · AI-generated

business construction energy corporate

The AS handle BLATTNER-HOLDING-COMPANY is held by Blattner Company.

What it's used for

  • The space carries a single corporate block, identified by the netname BH-945 and registrant Blattner Company.
  • The inventory consists of 256 IPv4 addresses within one prefix (192.65.178.0/24) and 0 IPv6 prefixes. With only 1 observed neighbour, this indicates an internal corporate estate rather than a transit or access network.

Notable

  • The RDAP registrant Blattner Company aligns directly with the AS holder name.
  • Blattner Company is the parent company of Blattner Energy and D.H. Blattner & Sons, both of which are members of the Quanta Services family.
  • The address inventory is a single /24 block, representing a small, self-contained corporate network.

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

1 upstream, 0 downstream and 1 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS11232Midcontinent Communications64

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-14, 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 1 prefixes · 256 addresses IPv6 0 prefixes

CountryNamePrefixes
USUnited States of America1

Registry

Allocation record

ARIN · via Atlas (registry + RDAP)
Registry
ARIN
Handle
AS19121
Registry name
BLATTNER-HOLDING-COMPANY
Registrant
Blattner Company
Abuse contact
NetworkAlerts@blattnerenergy.com
Registered
2020-01-14
Last changed
2020-01-14
Allocation
assigned

Routing security

RPKI and IRR

Full detail
RPKI
0% valid · 0 valid, 1 with no ROA
ROAs
0 authorising AS19121
ASPA
no ASPA record
IRR
100% registered · 1 of 1 announcements
Route objects
1 naming AS19121

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 1,771 prefixes, as published 2026-10-15. 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