ASN AS21756 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS21756?

AS21756 is listed under SIDERCA S.A.I.C..

What do peers, upstreams, and downstreams mean in ASN data?

Peers are lateral network interconnections, upstreams are transit providers, and downstreams are customer networks receiving connectivity.

What are routes and IP ranges for an ASN?

Routes and IP ranges are the network prefixes announced by the ASN on the internet and show the address space it originates.

Why is WHOIS data shown for an ASN?

WHOIS data provides registration and contact context for ASN ownership, administration, and operational reference.

How can I access the full ASN tables?

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AS21756 SIDERCA S.A.I.C. | IPGeolocation.io

ASN Lookup Tool

SIDERCA S.A.I.C. tenaris.com

AR 5 Routes

AS Data

AS21756

AS21756 – SIDERCA S.A.I.C.

AS Number	21756
AS Name	AR-ASTE1-LACNIC
Organization	SIDERCA S.A.I.C.
Country	AR
Website	tenaris.com
Number of IPv4 Routes	5
Number of IPv6 Routes	0
ASN type	BUSINESS
Registry	lacnic
Date Allocated	2001-06-15

ASN Intelligence API for production workflows

Use ASN data for AS21756 in automation: routing intelligence, peering analysis, ownership checks, and network observability.

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IP Ranges

Route	Origin	Origin Name	ISP	# IPs
200.1.117.0/24	AS21756	SIDERCA S.A.I.C.	SIDERCA S.A.I.C.	256
201.234.38.0/24	AS21756	SIDERCA S.A.I.C.	Cirion Technologies Argentina S.A.	256
200.80.222.0/24	AS21756	SIDERCA S.A.I.C.	SIDERCA S.A.I.C.	256
200.69.130.0/24	AS21756	SIDERCA S.A.I.C.	SIDERCA S.A.	256
200.9.229.0/24	AS21756	SIDERCA S.A.I.C.	SIDERCA S.A.I.C.	256

Raw Whois Response

% Joint Whois - whois.lacnic.net
%  This server accepts single ASN, IPv4 or IPv6 queries

% LACNIC resource: whois.lacnic.net


% Copyright LACNIC lacnic.net
%  The data below is provided for information purposes
%  and to assist persons in obtaining information about or
%  related to AS and IP numbers registrations
%  By submitting a whois query, you agree to use this data
%  only for lawful purposes.
%  2026-04-25 09:31:52 (-03 -03:00)

aut-num:     AS21756
owner:       SIDERCA S.A.I.C.
ownerid:     AR-ASTE1-LACNIC
responsible: Matias Marzullo
address:     Della Paolera, 299, Piso 12
address:     1001 - Buenos Aires - CF
country:     AR
phone:       +54  1159849432 [0000]
owner-c:     MAM715
routing-c:   MAM715
abuse-c:     MAM715
created:     20010615
changed:     20260318

nic-hdl:     MAM715
person:      Matias Marzullo
e-mail:      mmarzullo@tenaris.com
address:     dr simini, 250, 
address:      - Campana - buenos aires
country:     AR
phone:       +54  1159849432
created:     20250918
changed:     20250918

% whois.lacnic.net accepts only direct match queries.
% Types of queries are: POCs, ownerid, CIDR blocks, IP
% and AS numbers.


#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/resources/registry/whois/tou/
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
#
# Copyright 1997-2026, American Registry for Internet Numbers, Ltd.
#


ASNumber:       21756
ASName:         LACNIC-21756
ASHandle:       AS21756
RegDate:        2002-07-27
Updated:        2007-12-17
Comment:        This AS is under LACNIC responsibility for further allocations to
Comment:        users in LACNIC region.
Comment:        Please see http://www.lacnic.net/ for further details, or check the
Comment:        WHOIS server located at http://whois.lacnic.net
Ref:            https://rdap.arin.net/registry/autnum/21756

ResourceLink:  http://lacnic.net/cgi-bin/lacnic/whois
ResourceLink:  whois.lacnic.net


OrgName:        Latin American and Caribbean IP address Regional Registry
OrgId:          LACNIC
Address:        Rambla Republica de Mexico 6125
City:           Montevideo
StateProv:      
PostalCode:     11400
Country:        UY
RegDate:        2002-07-27
Updated:        2018-03-15
Ref:            https://rdap.arin.net/registry/entity/LACNIC

ReferralServer:  whois://whois.lacnic.net
ResourceLink:  http://lacnic.net/cgi-bin/lacnic/whois

OrgTechHandle: LACNIC-ARIN
OrgTechName:   LACNIC Whois Info
OrgTechPhone:  +598-2604-2222 
OrgTechEmail:  whois-contact@lacnic.net
OrgTechRef:    https://rdap.arin.net/registry/entity/LACNIC-ARIN

OrgAbuseHandle: LWI100-ARIN
OrgAbuseName:   LACNIC Whois Info
OrgAbusePhone:  +598-2604-2222 
OrgAbuseEmail:  abuse@lacnic.net
OrgAbuseRef:    https://rdap.arin.net/registry/entity/LWI100-ARIN


#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/resources/registry/whois/tou/
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
#
# Copyright 1997-2026, American Registry for Internet Numbers, Ltd.
#

Parsed Whois Response

{
  "status" : true,
  "whois_server" : "whois.arin.net",
  "aut_nums" : [ {
    "aut_num" : "21756",
    "as_handle" : "AS21756",
    "as_name" : "LACNIC-21756",
    "tech_contacts" : [ "LACNIC-ARIN" ],
    "abuse_contacts" : [ "LWI100-ARIN" ],
    "date_created" : "2002-07-27",
    "date_updated" : "2007-12-17",
    "source" : "https://rdap.arin.net/registry/autnum/21756"
  } ],
  "organization" : {
    "handle" : "LACNIC",
    "name" : "Latin American and Caribbean IP address Regional Registry",
    "address" : [ "Rambla Republica de Mexico 6125", "Montevideo", "11400", "UY" ],
    "street" : "Rambla Republica De Mexico",
    "city" : "Montevideo",
    "zip_code" : "11400",
    "country" : [ "UY" ],
    "date_created" : "2002-07-27",
    "date_updated" : "2018-03-15",
    "source" : "https://rdap.arin.net/registry/entity/LACNIC",
    "addressCountry" : "UY"
  },
  "technical_contacts" : [ {
    "handle" : "LACNIC-ARIN",
    "name" : "LACNIC Whois Info",
    "email" : [ "whois-contact@lacnic.net" ],
    "phone" : [ "+598-2604-2222" ],
    "source" : "https://rdap.arin.net/registry/entity/LACNIC-ARIN"
  } ],
  "abuse_contacts" : [ {
    "handle" : "LWI100-ARIN",
    "name" : "LACNIC Whois Info",
    "email" : [ "abuse@lacnic.net" ],
    "phone" : [ "+598-2604-2222" ],
    "source" : "https://rdap.arin.net/registry/entity/LWI100-ARIN"
  } ]
}

Peers

AS Number	Description	Country
AS11664	Techtel LMDS Comunicaciones Interactivas S.A.	AR
AS64524	-Private Use AS-, ZZ	ZZ
AS3549	Level 3 Communications, Inc. (GBLX)	US
AS3549	Level 3 Parent, LLC	US
AS11014	CPS	AR

Upstreams

AS Number	Description	Country
AS11664	Techtel LMDS Comunicaciones Interactivas S.A.	AR
AS3549	Level 3 Parent, LLC	US
AS11014	CPS	AR