Autonomous system
AS21756 SIDERCA S.A.I.C.
Unclassified APNIC
Summary
Siderca S.A.I.C.
business industrial argentina steel
AS21756 is operated by Siderca S.A.I.C., an Argentine steel tube producer.
What it's used for
- The address space is registered under netnames matching the holder, such as
200.1.117.0 - 200.1.117.255and200.9.229.0 - 200.9.229.255, indicating internal corporate usage. - The AS announces 1280 IPv4 addresses across 5 prefixes with 3 observed neighbours, a ratio consistent with a small internal corporate estate rather than a public access or transit network.
Notable
- Four of the five prefixes are registered to Siderca S.A.I.C., while 201.234.38.0/24 is registered to Cirion Technologies Argentina S.A., suggesting a leased or third-party managed segment.
- Siderca S.A.I.C. operates as a subsidiary of Tenaris S.A., a global steel tube manufacturer controlled by the Techint group.
- The inventory consists of five /24 blocks, all located in Argentina, with no IPv6 prefixes announced.
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 5 prefixes · 1.28K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| AR | Argentina | 5 |
Registry
Allocation record
- Registry
- APNIC
- Handle
AS21756- Registry name
- 21756
- Registrant
- SIDERCA S.A.I.C.
- Abuse contact
- mmarzullo@tenaris.com
- Registered
- 2001-06-15
- Last changed
- 2026-03-18
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 100% valid · 5 valid, 0 with no ROA
- ROAs
- 6 authorising AS21756
- ASPA
- no ASPA record
- IRR
- 100% registered · 5 of 5 announcements
- Route objects
- 8 naming AS21756
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