ASN AS40016 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS40016?

AS40016 is listed under MESIROW FINANCIAL HOLDINGS, 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.

AS40016 MESIROW FINANCIAL HOLDINGS, INC.

ASN Lookup Tool

MESIROW FINANCIAL HOLDINGS, INC. mesirowfinancial.com

US 2 Routes

AS Data

AS40016

AS40016 – MESIROW FINANCIAL HOLDINGS, INC.

AS Number	40016
AS Name	MESIROW
Organization	MESIROW FINANCIAL HOLDINGS, INC.(mfh-7)
Country	US
Website	mesirowfinancial.com
Number of IPv4 Routes	2
Number of IPv6 Routes	0
ASN type	BUSINESS
Registry	ARIN
Date Allocated	2006-06-07

ASN Intelligence API for production workflows

Use ASN data for AS40016 in automation: routing intelligence, peering analysis, ownership checks, and network observability.

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IP Ranges

Route	Origin	Origin Name	ISP	# IPs
204.153.74.0/24	AS40016	MESIROW FINANCIAL HOLDINGS, INC.	Mesirow Financial	256
207.252.173.0/24	AS40016	MESIROW FINANCIAL HOLDINGS, INC.	Mesirow Financial	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:       40016
ASName:         MESIROW
ASHandle:       AS40016
RegDate:        2006-06-07
Updated:        2006-06-07    
Ref:            https://rdap.arin.net/registry/autnum/40016


OrgName:        MESIROW FINANCIAL HOLDINGS, INC.
OrgId:          MFH-7
Address:        350 N CLARK ST
City:           CHICAGO
StateProv:      IL
PostalCode:     60610
Country:        US
RegDate:        2006-05-18
Updated:        2014-10-28
Ref:            https://rdap.arin.net/registry/entity/MFH-7


OrgAbuseHandle: PDO24-ARIN
OrgAbuseName:   Dockins, Paul 
OrgAbusePhone:  +1-312-595-6943 
OrgAbuseEmail:  pdockins@mesirowfinancial.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/PDO24-ARIN

OrgTechHandle: STEVE130-ARIN
OrgTechName:   Wiley, Steven A
OrgTechPhone:  +1-312-595-6258 
OrgTechEmail:  swiley@mesirowfinancial.com
OrgTechRef:    https://rdap.arin.net/registry/entity/STEVE130-ARIN

OrgTechHandle: PL345-ARIN
OrgTechName:   Letarte, Phil 
OrgTechPhone:  +1-312-595-6258 
OrgTechEmail:  pletarte@mesirowfinancial.com
OrgTechRef:    https://rdap.arin.net/registry/entity/PL345-ARIN

OrgTechHandle: PDO24-ARIN
OrgTechName:   Dockins, Paul 
OrgTechPhone:  +1-312-595-6943 
OrgTechEmail:  pdockins@mesirowfinancial.com
OrgTechRef:    https://rdap.arin.net/registry/entity/PDO24-ARIN

RTechHandle: PL345-ARIN
RTechName:   Letarte, Phil 
RTechPhone:  +1-312-595-6258 
RTechEmail:  pletarte@mesirowfinancial.com
RTechRef:    https://rdap.arin.net/registry/entity/PL345-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
AS1239	Cogent Communications, LLC	US
AS3356	Level 3 Parent, LLC	US
AS23352	DEFT.COM	US
AS174	Cogent Communications, LLC	US

Upstreams

AS Number	Description	Country
AS3356	Level 3 Parent, LLC	US
AS23352	DEFT.COM	US
AS174	Cogent Communications, LLC	US