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AS40016 MESIROW FINANCIAL HOLDINGS, INC.

Q: Why is WHOIS data shown for an ASN?

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

ASN Lookup Tool

MESIROW FINANCIAL HOLDINGS, INC. mesirow.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	mesirow.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:        2026-09-25
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:        2026-09-25
Ref:            https://rdap.arin.net/registry/entity/MFH-7


OrgTechHandle: RASHE19-ARIN
OrgTechName:   Rashev, Kamen 
OrgTechPhone:  +1-312-978-9212 
OrgTechEmail:  kamen.rashev@mesirow.com
OrgTechRef:    https://rdap.arin.net/registry/entity/RASHE19-ARIN

OrgAbuseHandle: RASHE19-ARIN
OrgAbuseName:   Rashev, Kamen 
OrgAbusePhone:  +1-312-978-9212 
OrgAbuseEmail:  kamen.rashev@mesirow.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/RASHE19-ARIN

OrgTechHandle: PLRJ-ARIN
OrgTechName:   rhone jr, perry l
OrgTechPhone:  +1-312-595-8464 
OrgTechEmail:  perry.rhone@mesirow.com
OrgTechRef:    https://rdap.arin.net/registry/entity/PLRJ-ARIN

OrgAbuseHandle: PLRJ-ARIN
OrgAbuseName:   rhone jr, perry l
OrgAbusePhone:  +1-312-595-8464 
OrgAbuseEmail:  perry.rhone@mesirow.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/PLRJ-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" : "40016",
    "as_handle" : "AS40016",
    "as_name" : "MESIROW",
    "tech_contacts" : [ "RASHE19-ARIN", "PLRJ-ARIN" ],
    "abuse_contacts" : [ "RASHE19-ARIN", "PLRJ-ARIN" ],
    "date_created" : "2006-06-07",
    "date_updated" : "2026-09-25",
    "source" : "https://rdap.arin.net/registry/autnum/40016"
  } ],
  "organization" : {
    "handle" : "MFH-7",
    "name" : "MESIROW FINANCIAL HOLDINGS, INC.",
    "address" : [ "350 N CLARK ST", "CHICAGO", "IL", "60610", "US" ],
    "street" : "N Clark St",
    "city" : "Chicago",
    "state" : "IL",
    "zip_code" : "60610",
    "country" : [ "US" ],
    "date_created" : "2006-05-18",
    "date_updated" : "2026-09-25",
    "source" : "https://rdap.arin.net/registry/entity/MFH-7",
    "addressCountry" : "US"
  },
  "technical_contacts" : [ {
    "handle" : "RASHE19-ARIN",
    "name" : "Rashev, Kamen",
    "email" : [ "kamen.rashev@mesirow.com" ],
    "phone" : [ "+1-312-978-9212" ],
    "source" : "https://rdap.arin.net/registry/entity/RASHE19-ARIN"
  }, {
    "handle" : "PLRJ-ARIN",
    "name" : "rhone jr, perry l",
    "email" : [ "perry.rhone@mesirow.com" ],
    "phone" : [ "+1-312-595-8464" ],
    "source" : "https://rdap.arin.net/registry/entity/PLRJ-ARIN"
  } ],
  "abuse_contacts" : [ {
    "handle" : "RASHE19-ARIN",
    "name" : "Rashev, Kamen",
    "email" : [ "kamen.rashev@mesirow.com" ],
    "phone" : [ "+1-312-978-9212" ],
    "source" : "https://rdap.arin.net/registry/entity/RASHE19-ARIN"
  }, {
    "handle" : "PLRJ-ARIN",
    "name" : "rhone jr, perry l",
    "email" : [ "perry.rhone@mesirow.com" ],
    "phone" : [ "+1-312-595-8464" ],
    "source" : "https://rdap.arin.net/registry/entity/PLRJ-ARIN"
  } ]
}

Peers

AS Number	Description	Country
AS1239	Cogent Communications, LLC	US
AS3356	Level 3 Parent, LLC	US
AS174	Cogent Communications, LLC	US
AS23352	DEFT.COM	US

Upstreams

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

Frequently Asked Questions

What is ASN AS40016?

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?

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 included here?

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

How can I access full ASN table data?

This page previews large ASN datasets. Use See more to load additional rows, and upgrade your plan to view complete peer, route, upstream, and downstream data.