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.

AS30573 Old Second Bancorp | IPGeolocation.io

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

Old Second Bancorp oldsecond.com

US 1 Routes

AS Data

AS30573

AS30573 – Old Second Bancorp

AS Number	30573
AS Name	OLDSECONDBANCORP
Organization	Old Second Bancorp(osb-9)
Country	US
Website	oldsecond.com
Number of IPv4 Routes	1
Number of IPv6 Routes	0
ASN type	BUSINESS
Registry	ARIN
Date Allocated	2003-11-11

ASN Intelligence API for production workflows

Use ASN data for AS30573 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

Get ASN API Key ASN API Docs

IP Ranges

Route	Origin	Origin Name	ISP	# IPs
12.48.114.0/24	AS30573	Old Second Bancorp	OLD SECOND BANCORP 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:       30573
ASName:         OLDSECONDBANCORP
ASHandle:       AS30573
RegDate:        2003-11-11
Updated:        2012-03-02    
Ref:            https://rdap.arin.net/registry/autnum/30573


OrgName:        Old Second Bancorp
OrgId:          OSB-9
Address:        37 South River Street
City:           Aurora
StateProv:      IL
PostalCode:     60506-4172
Country:        US
RegDate:        2003-08-27
Updated:        2011-09-24
Ref:            https://rdap.arin.net/registry/entity/OSB-9


OrgTechHandle: HOSTM308-ARIN
OrgTechName:   HOSTMASTER
OrgTechPhone:  +1-630-892-0202 
OrgTechEmail:  bschluntz@oldsecond.com
OrgTechRef:    https://rdap.arin.net/registry/entity/HOSTM308-ARIN

OrgAbuseHandle: HOSTM308-ARIN
OrgAbuseName:   HOSTMASTER
OrgAbusePhone:  +1-630-892-0202 
OrgAbuseEmail:  bschluntz@oldsecond.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/HOSTM308-ARIN

RTechHandle: HOSTM308-ARIN
RTechName:   HOSTMASTER
RTechPhone:  +1-630-892-0202 
RTechEmail:  bschluntz@oldsecond.com
RTechRef:    https://rdap.arin.net/registry/entity/HOSTM308-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
AS33491	Comcast Cable Communications, LLC	US
AS7018	AT&T Enterprises, LLC	US

Upstreams

AS Number	Description	Country
AS33491	Comcast Cable Communications, LLC	US
AS7018	AT&T Enterprises, LLC	US

Frequently Asked Questions

What is ASN AS30573?

ASN AS30573 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS30573?

AS30573 is listed under Old Second Bancorp.

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.