ASN AS21589 is an Autonomous System Number used to identify a network for BGP internet routing.

Who manages ASN AS21589?

AS21589 is listed under City of San Jose.

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.

AS21589 City of San Jose | IPGeolocation.io

ASN Lookup Tool

City of San Jose sanjoseca.gov

US 26 Routes

AS Data

AS21589

AS21589 – City of San Jose

AS Number	21589
AS Name	CSJ-INTERNET
Organization	City of San Jose(csj-1)
Country	US
Website	sanjoseca.gov
Number of IPv4 Routes	25
Number of IPv6 Routes	1
ASN type	GOVERNMENT
Registry	ARIN
Date Allocated	2012-10-04

ASN Intelligence API for production workflows

Use ASN data for AS21589 in automation: routing intelligence, peering analysis, ownership checks, and network observability.

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IP Ranges

Route	Origin	Origin Name	ISP	# IPs
156.39.60.0/24	AS21589	City of San Jose	City of San Jose	256
156.39.0.0/24	AS21589	City of San Jose	City of San Jose	256
156.39.73.0/24	AS21589	City of San Jose	City of San Jose	256
156.39.64.0/22	AS21589	City of San Jose	City of San Jose	1024
156.39.69.0/24	AS21589	City of San Jose	City of San Jose	256
156.39.136.0/21	AS21589	City of San Jose	City of San Jose	2048
156.39.125.0/24	AS21589	City of San Jose	City of San Jose	256
156.39.99.0/24	AS21589	City of San Jose	City of San Jose	256
156.39.131.0/24	AS21589	City of San Jose	City of San Jose	256
156.39.13.0/24	AS21589	City of San Jose	City of San Jose	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:       21589
ASName:         CSJ-INTERNET
ASHandle:       AS21589
RegDate:        2012-10-04
Updated:        2012-10-04    
Ref:            https://rdap.arin.net/registry/autnum/21589


OrgName:        City of San Jose
OrgId:          CSJ-1
Address:        200 E. Santa Clara St.
City:           San Jose
StateProv:      CA
PostalCode:     95113
Country:        US
RegDate:        1991-12-09
Updated:        2019-05-21
Ref:            https://rdap.arin.net/registry/entity/CSJ-1


OrgTechHandle: DNSAD188-ARIN
OrgTechName:   DNS Admins
OrgTechPhone:  +1-408-793-6831 
OrgTechEmail:  NetworkGroup@sanjoseca.gov
OrgTechRef:    https://rdap.arin.net/registry/entity/DNSAD188-ARIN

OrgAbuseHandle: DNSAD188-ARIN
OrgAbuseName:   DNS Admins
OrgAbusePhone:  +1-408-793-6831 
OrgAbuseEmail:  NetworkGroup@sanjoseca.gov
OrgAbuseRef:    https://rdap.arin.net/registry/entity/DNSAD188-ARIN

OrgTechHandle: CASTI255-ARIN
OrgTechName:   Castillo, James 
OrgTechPhone:  +1-408-793-6809 
OrgTechEmail:  james.castillo@sanjoseca.gov
OrgTechRef:    https://rdap.arin.net/registry/entity/CASTI255-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
AS6939	Hurricane Electric LLC	US
AS286	GTT Communications Inc.	NL
AS286	GTT Communications Inc.	US
AS3257	GTT Communications Inc.	US

Upstreams

AS Number	Description	Country
AS7018	AT&T Enterprises, LLC	US
AS6939	Hurricane Electric LLC	US
AS286	GTT Communications Inc.	US
AS3257	GTT Communications Inc.	US