Autonomous system
AS26551 SARGENT-AND-LUNDY
Unclassified ARIN
Summary
Sargent & Lundy
business engineering corporate internal
The AS handle SARGENT-AND-LUNDY is held by Sargent & Lundy Engineers.
What it's used for
- The address space carries internal corporate infrastructure, evidenced by reverse DNS entries pointing to
host.sargentlundy.comand netnames consistently labeledSLCHICAGO. - The AS announces 65,536 IPv4 addresses across 12 prefixes with only 3 observed neighbours, a ratio that indicates an internal corporate estate rather than a transit or access network.
Notable
- All registrants for the announced prefixes are listed as Sargent & Lundy Engineers, fully agreeing with the AS holder.
- The address inventory is finely subdivided into 12 distinct prefixes, reflecting site-by-site segmentation typical of a large engineering firm's internal 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
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 2026-10-13, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 12 prefixes · 65.54K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 12 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS26551- Registry name
- SARGENT-AND-LUNDY
- Registrant
- Sargent & Lundy Engineers
- Abuse contact
- mohammed.chouikh@sargentlundy.com
- Registered
- 2002-10-15
- Last changed
- 2012-03-02
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 5 with no ROA
- ROAs
- 0 authorising AS26551
- ASPA
- no ASPA record
- IRR
- 0% registered · 0 of 5 announcements
- Route objects
- 0 naming AS26551
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 1,773 prefixes, as published 2026-10-13. 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