ASN AS3743 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS3743?

AS3743 is listed under Cleveland Cliffs Steel LLC.

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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AS3743 Cleveland Cliffs Steel LLC

ASN Lookup Tool

Cleveland Cliffs Steel LLC clevelandcliffs.com

US 7 Routes

AS Data

AS3743

AS3743 – Cleveland Cliffs Steel LLC

AS Number	3743
AS Name	ARCEL-2
Organization	Cleveland Cliffs Steel LLC (arcel-2)
Country	US
Website	clevelandcliffs.com
Number of IPv4 Routes	7
Number of IPv6 Routes	0
ASN type	BUSINESS
Registry	ARIN
Date Allocated	2009-09-09

ASN Intelligence API for production workflows

Use ASN data for AS3743 in automation: routing intelligence, peering analysis, ownership checks, and network observability.

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IP Ranges

Route	Origin	Origin Name	ISP	# IPs
156.144.51.0/24	AS3743	Cleveland Cliffs Steel LLC	Cleveland Cliffs Steel LLC	256
156.144.100.0/24	AS3743	Cleveland Cliffs Steel LLC	Cleveland Cliffs Steel LLC	256
156.144.249.0/24	AS3743	Cleveland Cliffs Steel LLC	Cleveland Cliffs Steel LLC	256
156.144.108.0/24	AS3743	Cleveland Cliffs Steel LLC	Cleveland Cliffs Steel LLC	256
156.144.99.0/24	AS3743	Cleveland Cliffs Steel LLC	Cleveland Cliffs Steel LLC	256
156.144.208.0/24	AS3743	Cleveland Cliffs Steel LLC	Cleveland Cliffs Steel LLC	256
156.144.109.0/24	AS3743	Cleveland Cliffs Steel LLC	Cleveland Cliffs Steel LLC	256

Raw Whois Response

#
# 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:       3743
ASName:         ARCEL-2
ASHandle:       AS3743
RegDate:        2009-09-09
Updated:        2023-06-30
Comment:        WDS3-ARIN00
Ref:            https://rdap.arin.net/registry/autnum/3743


OrgName:        Cleveland Cliffs Steel LLC
OrgId:          ARCEL-2
Address:        1 SOUTH DEARBORN, 19TH FLOOR
City:           CHICAGO
StateProv:      IL
PostalCode:     60603
Country:        US
RegDate:        2009-08-14
Updated:        2025-11-24
Ref:            https://rdap.arin.net/registry/entity/ARCEL-2


OrgNOCHandle: ABUSE9467-ARIN
OrgNOCName:   Abuse
OrgNOCPhone:  +1-216-694-5700 
OrgNOCEmail:  arinadmin@clevelandcliffs.com
OrgNOCRef:    https://rdap.arin.net/registry/entity/ABUSE9467-ARIN

OrgTechHandle: ABUSE9467-ARIN
OrgTechName:   Abuse
OrgTechPhone:  +1-216-694-5700 
OrgTechEmail:  arinadmin@clevelandcliffs.com
OrgTechRef:    https://rdap.arin.net/registry/entity/ABUSE9467-ARIN

OrgAbuseHandle: ABUSE9467-ARIN
OrgAbuseName:   Abuse
OrgAbusePhone:  +1-216-694-5700 
OrgAbuseEmail:  arinadmin@clevelandcliffs.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/ABUSE9467-ARIN

RNOCHandle: MPC47-ARIN
RNOCName:   Collins, Michelle P
RNOCPhone:  +1-724-284-2034 
RNOCEmail:  michelle.collins@clevelandcliffs.com
RNOCRef:    https://rdap.arin.net/registry/entity/MPC47-ARIN

RTechHandle: MPC47-ARIN
RTechName:   Collins, Michelle P
RTechPhone:  +1-724-284-2034 
RTechEmail:  michelle.collins@clevelandcliffs.com
RTechRef:    https://rdap.arin.net/registry/entity/MPC47-ARIN

RAbuseHandle: MPC47-ARIN
RAbuseName:   Collins, Michelle P
RAbusePhone:  +1-724-284-2034 
RAbuseEmail:  michelle.collins@clevelandcliffs.com
RAbuseRef:    https://rdap.arin.net/registry/entity/MPC47-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" : "3743",
    "as_handle" : "AS3743",
    "as_name" : "ARCEL-2",
    "tech_contacts" : [ "ABUSE9467-ARIN", "MPC47-ARIN" ],
    "abuse_contacts" : [ "ABUSE9467-ARIN", "MPC47-ARIN" ],
    "date_created" : "2009-09-09",
    "date_updated" : "2023-06-30",
    "source" : "https://rdap.arin.net/registry/autnum/3743"
  } ],
  "organization" : {
    "handle" : "ARCEL-2",
    "name" : "Cleveland Cliffs Steel LLC",
    "address" : [ "1 SOUTH DEARBORN, 19TH FLOOR", "CHICAGO", "IL", "60603", "US" ],
    "street" : "South Dearborn",
    "city" : "Chicago",
    "state" : "IL",
    "zip_code" : "60603",
    "country" : [ "US" ],
    "date_created" : "2009-08-14",
    "date_updated" : "2025-11-24",
    "source" : "https://rdap.arin.net/registry/entity/ARCEL-2",
    "addressCountry" : "US"
  },
  "technical_contacts" : [ {
    "handle" : "ABUSE9467-ARIN",
    "name" : "Abuse",
    "email" : [ "arinadmin@clevelandcliffs.com" ],
    "phone" : [ "+1-216-694-5700" ],
    "source" : "https://rdap.arin.net/registry/entity/ABUSE9467-ARIN"
  }, {
    "handle" : "MPC47-ARIN",
    "name" : "Collins, Michelle P",
    "email" : [ "michelle.collins@clevelandcliffs.com" ],
    "phone" : [ "+1-724-284-2034" ],
    "source" : "https://rdap.arin.net/registry/entity/MPC47-ARIN"
  } ],
  "abuse_contacts" : [ {
    "handle" : "ABUSE9467-ARIN",
    "name" : "Abuse",
    "email" : [ "arinadmin@clevelandcliffs.com" ],
    "phone" : [ "+1-216-694-5700" ],
    "source" : "https://rdap.arin.net/registry/entity/ABUSE9467-ARIN"
  }, {
    "handle" : "MPC47-ARIN",
    "name" : "Collins, Michelle P",
    "email" : [ "michelle.collins@clevelandcliffs.com" ],
    "phone" : [ "+1-724-284-2034" ],
    "source" : "https://rdap.arin.net/registry/entity/MPC47-ARIN"
  } ]
}

Peers

AS Number	Description	Country
AS209	CenturyLink Communications, LLC	US

Upstreams

AS Number	Description	Country
AS209	CenturyLink Communications, LLC	US