What is ASN AS400203?

ASN AS400203 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS400203?

AS400203 is listed under Big Y.

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.

AS400203 Big Y | IPGeolocation.io

ASN Lookup Tool

Big Y bigy.com

US 1 Routes

AS Data

AS400203

AS400203 – Big Y

AS Number	400203
AS Name	BYF-MH-01
Organization	Big Y(byf-10)
Country	US
Website	bigy.com
Number of IPv4 Routes	1
Number of IPv6 Routes	0
ASN type	BUSINESS
Registry	ARIN
Date Allocated	2021-11-05

ASN Intelligence API for production workflows

Use ASN data for AS400203 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
50.231.225.0/24	AS400203	Big Y	Comcast Cable Communications, LLC	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:       400203
ASName:         BYF-MH-01
ASHandle:       AS400203
RegDate:        2021-11-05
Updated:        2021-11-05    
Ref:            https://rdap.arin.net/registry/autnum/400203


OrgName:        Big Y
OrgId:          BYF-10
Address:        2145 Roosevelt Ave
Address:        PO Box 7840
City:           Springfield
StateProv:      MA
PostalCode:     01102-7840
Country:        US
RegDate:        2021-10-26
Updated:        2021-10-26
Ref:            https://rdap.arin.net/registry/entity/BYF-10


OrgNOCHandle: MNHS-ARIN
OrgNOCName:   Manager of Networks and Hardware Support
OrgNOCPhone:  +1-413-504-4444 
OrgNOCEmail:  isnetworking@bigy.com
OrgNOCRef:    https://rdap.arin.net/registry/entity/MNHS-ARIN

OrgTechHandle: MNHS-ARIN
OrgTechName:   Manager of Networks and Hardware Support
OrgTechPhone:  +1-413-504-4444 
OrgTechEmail:  isnetworking@bigy.com
OrgTechRef:    https://rdap.arin.net/registry/entity/MNHS-ARIN

OrgDNSHandle: MNHS-ARIN
OrgDNSName:   Manager of Networks and Hardware Support
OrgDNSPhone:  +1-413-504-4444 
OrgDNSEmail:  isnetworking@bigy.com
OrgDNSRef:    https://rdap.arin.net/registry/entity/MNHS-ARIN

OrgAbuseHandle: MNHS-ARIN
OrgAbuseName:   Manager of Networks and Hardware Support
OrgAbusePhone:  +1-413-504-4444 
OrgAbuseEmail:  isnetworking@bigy.com
OrgAbuseRef:    https://rdap.arin.net/registry/entity/MNHS-ARIN

OrgRoutingHandle: MNHS-ARIN
OrgRoutingName:   Manager of Networks and Hardware Support
OrgRoutingPhone:  +1-413-504-4444 
OrgRoutingEmail:  isnetworking@bigy.com
OrgRoutingRef:    https://rdap.arin.net/registry/entity/MNHS-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
AS46887	Crown Castle Fiber LLC	US
AS7015	Comcast Cable Communications, LLC	US

Upstreams

AS Number	Description	Country
AS46887	Crown Castle Fiber LLC	US
AS7015	Comcast Cable Communications, LLC	US