ASN AS19858 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS19858?

AS19858 is listed under M. Arthur Gensler Jr. & Associates, Inc..

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?

The page shows a preview of large ASN datasets. Use the page controls to load more rows, and upgrade to a paid plan for complete access.

AS19858 M. Arthur Gensler Jr. & Associates, Inc.

ASN Lookup Tool

M. Arthur Gensler Jr. & Associates, Inc. gensler.com

US 2 Routes

AS Data

AS19858

AS19858 – M. Arthur Gensler Jr. & Associates, Inc.

AS Number	19858
AS Name	GENSLER
Organization	M. Arthur Gensler Jr. & Associates, Inc.(gaa)
Country	US
Website	gensler.com
Number of IPv4 Routes	2
Number of IPv6 Routes	0
ASN type	BUSINESS
Registry	ARIN
Date Allocated	2001-02-21

ASN Intelligence API for production workflows

Use ASN data for AS19858 in automation: routing intelligence, peering analysis, ownership checks, and network observability.

Access complete peers, upstreams, downstreams, routes, WHOIS, and contact intelligence via our API. Learn more

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IP Ranges

Route	Origin	Origin Name	ISP	# IPs
64.239.73.0/24	AS19858	M. Arthur Gensler Jr. & Associates, Inc.	M. Arthur Gensler Jr. & Associates, Inc.	256
64.239.72.0/24	AS19858	M. Arthur Gensler Jr. & Associates, Inc.	M. Arthur Gensler Jr. & Associates, Inc.	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:       19858
ASName:         GENSLER
ASHandle:       AS19858
RegDate:        2001-02-21
Updated:        2025-06-30    
Ref:            https://rdap.arin.net/registry/autnum/19858


OrgName:        M. Arthur Gensler Jr. & Associates, Inc.
OrgId:          GAA
Address:        2101 Webster St.
Address:        Suite 2000
City:           Oakland
StateProv:      CA
PostalCode:     94612
Country:        US
RegDate:        1990-05-29
Updated:        2025-06-30
Ref:            https://rdap.arin.net/registry/entity/GAA


OrgAbuseHandle: BALTE2-ARIN
OrgAbuseName:   Baltera, Matthew 
OrgAbusePhone:  +1-832-496-8696 
OrgAbuseEmail:  matthew_baltera@gensler.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/BALTE2-ARIN

OrgTechHandle: NDE44-ARIN
OrgTechName:   Eigsti, Nathan Daniel
OrgTechPhone:  +1-720-557-5228 
OrgTechEmail:  nathan_eigsti@gensler.com
OrgTechRef:    https://rdap.arin.net/registry/entity/NDE44-ARIN

OrgTechHandle: HEROL-ARIN
OrgTechName:   HEROLD, LORI 
OrgTechPhone:  +1-415-836-4265 
OrgTechEmail:  lori_herold@gensler.com
OrgTechRef:    https://rdap.arin.net/registry/entity/HEROL-ARIN

OrgRoutingHandle: NDE44-ARIN
OrgRoutingName:   Eigsti, Nathan Daniel
OrgRoutingPhone:  +1-720-557-5228 
OrgRoutingEmail:  nathan_eigsti@gensler.com
OrgRoutingRef:    https://rdap.arin.net/registry/entity/NDE44-ARIN

OrgAbuseHandle: NDE44-ARIN
OrgAbuseName:   Eigsti, Nathan Daniel
OrgAbusePhone:  +1-720-557-5228 
OrgAbuseEmail:  nathan_eigsti@gensler.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/NDE44-ARIN

OrgNOCHandle: NDE44-ARIN
OrgNOCName:   Eigsti, Nathan Daniel
OrgNOCPhone:  +1-720-557-5228 
OrgNOCEmail:  nathan_eigsti@gensler.com
OrgNOCRef:    https://rdap.arin.net/registry/entity/NDE44-ARIN

OrgRoutingHandle: BALTE2-ARIN
OrgRoutingName:   Baltera, Matthew 
OrgRoutingPhone:  +1-832-496-8696 
OrgRoutingEmail:  matthew_baltera@gensler.com
OrgRoutingRef:    https://rdap.arin.net/registry/entity/BALTE2-ARIN

OrgTechHandle: RANEY3-ARIN
OrgTechName:   RANEY, MAUREEN 
OrgTechPhone:  +1-303-893-7129 
OrgTechEmail:  maureen_raney@gensler.com
OrgTechRef:    https://rdap.arin.net/registry/entity/RANEY3-ARIN

OrgTechHandle: LAB21-ARIN
OrgTechName:   Bedrick, Lauren  Ashley
OrgTechPhone:  +1-702-560-5616 
OrgTechEmail:  arin2@brandergroup.net
OrgTechRef:    https://rdap.arin.net/registry/entity/LAB21-ARIN

OrgNOCHandle: BALTE2-ARIN
OrgNOCName:   Baltera, Matthew 
OrgNOCPhone:  +1-832-496-8696 
OrgNOCEmail:  matthew_baltera@gensler.com
OrgNOCRef:    https://rdap.arin.net/registry/entity/BALTE2-ARIN

OrgTechHandle: BALTE2-ARIN
OrgTechName:   Baltera, Matthew 
OrgTechPhone:  +1-832-496-8696 
OrgTechEmail:  matthew_baltera@gensler.com
OrgTechRef:    https://rdap.arin.net/registry/entity/BALTE2-ARIN

RTechHandle: BALTE2-ARIN
RTechName:   Baltera, Matthew 
RTechPhone:  +1-832-496-8696 
RTechEmail:  matthew_baltera@gensler.com
RTechRef:    https://rdap.arin.net/registry/entity/BALTE2-ARIN

RAbuseHandle: BALTE2-ARIN
RAbuseName:   Baltera, Matthew 
RAbusePhone:  +1-832-496-8696 
RAbuseEmail:  matthew_baltera@gensler.com
RAbuseRef:    https://rdap.arin.net/registry/entity/BALTE2-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
AS7018	AT&T Enterprises, LLC	US
AS6994	Fastmetrics	US
AS1239	Cogent Communications, LLC	US
AS174	Cogent Communications, LLC	US

Upstreams

AS Number	Description	Country
AS7018	AT&T Enterprises, LLC	US
AS6994	Fastmetrics	US
AS174	Cogent Communications, LLC	US