ASN AS15258 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS15258?

AS15258 is listed under Gilbane Building Company.

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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AS15258 Gilbane Building Company

ASN Lookup Tool

Gilbane Building Company gilbaneco.com

US 3 Routes

AS Data

AS15258

AS15258 – Gilbane Building Company

AS Number	15258
AS Name	GBCO
Organization	Gilbane Building Company(gilba-2)
Country	US
Website	gilbaneco.com
Number of IPv4 Routes	3
Number of IPv6 Routes	0
ASN type	BUSINESS
Registry	ARIN
Date Allocated	2009-01-13

ASN Intelligence API for production workflows

Use ASN data for AS15258 in automation: routing intelligence, peering analysis, ownership checks, and network observability.

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IP Ranges

Route	Origin	Origin Name	ISP	# IPs
204.90.13.0/24	AS15258	Gilbane Building Company	Gilbane Building Company	256
204.90.12.0/24	AS15258	Gilbane Building Company	Gilbane Building Company	256
204.90.14.0/24	AS15258	Gilbane Building Company	Gilbane Building Company	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:       15258
ASName:         GBCO
ASHandle:       AS15258
RegDate:        2009-01-13
Updated:        2012-02-24    
Ref:            https://rdap.arin.net/registry/autnum/15258


OrgName:        Gilbane Building Company
OrgId:          GILBA-2
Address:        7 Jackson Walkway
City:           Providence
StateProv:      RI
PostalCode:     02903
Country:        US
RegDate:        2008-11-20
Updated:        2024-09-30
Ref:            https://rdap.arin.net/registry/entity/GILBA-2


OrgAbuseHandle: WDA28-ARIN
OrgAbuseName:   Dalton, Will 
OrgAbusePhone:  +1-401-456-5948 
OrgAbuseEmail:  Networking-Team@gilbaneco.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/WDA28-ARIN

OrgTechHandle: OSOJN1-ARIN
OrgTechName:   Osojnicki, Jen 
OrgTechPhone:  +1-401-640-1695 
OrgTechEmail:  josojnicki@gilbaneco.com
OrgTechRef:    https://rdap.arin.net/registry/entity/OSOJN1-ARIN

OrgTechHandle: WDA28-ARIN
OrgTechName:   Dalton, Will 
OrgTechPhone:  +1-401-456-5948 
OrgTechEmail:  Networking-Team@gilbaneco.com
OrgTechRef:    https://rdap.arin.net/registry/entity/WDA28-ARIN

OrgNOCHandle: WDA28-ARIN
OrgNOCName:   Dalton, Will 
OrgNOCPhone:  +1-401-456-5948 
OrgNOCEmail:  Networking-Team@gilbaneco.com
OrgNOCRef:    https://rdap.arin.net/registry/entity/WDA28-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

Peers

AS Number	Description	Country
AS15830	Equinix EMEA Acquisition Enterprises B.V.	NL
AS15830	Equinix (EMEA) Acquisition Enterprises B.V.	NL
AS22773	Cox Communications Inc.	US

Upstreams

AS Number	Description	Country
AS15830	Equinix EMEA Acquisition Enterprises B.V.	NL
AS22773	Cox Communications Inc.	US