THE INTERNET, IN CONTEXT

Every name.
A world behind it.

Look beyond the address.
Discover the domains, networks and identities that connect us.

+WHOIS · RDAP · WEB3OPEN TO EXPLORE
/

A few places to start

No sign-up needed
02 / THE DETAILS0.27s
IP / NETWORK

128.138.43.2

Record retrieved
At a glance01
Query
128.138.43.2
IP range
128.138.0.0 - 128.138.255.255
CIDR
128.138.0.0/16
Network name
COLORADO
Organization
University of Colorado
Country / region
US
More to the name02
Source
whois.arin.net

The original response is preserved below for a closer look.

Under the surfaceRAW RESPONSE
whois.arin.net
#
# 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.
#


#
# Query terms are ambiguous.  The query is assumed to be:
#     "n 128.138.43.2"
#
# Use "?" to get help.
#

NetRange:       128.138.0.0 - 128.138.255.255
CIDR:           128.138.0.0/16
NetName:        COLORADO
NetHandle:      NET-128-138-0-0-1
Parent:         NET128 (NET-128-0-0-0-0)
NetType:        Direct Allocation
OriginAS:       
Organization:   University of Colorado (UNIVER-24)
RegDate:        1986-07-14
Updated:        2021-12-14
Ref:            https://rdap.arin.net/registry/ip/128.138.0.0


OrgName:        University of Colorado
OrgId:          UNIVER-24
Address:        Office of Information Technology
Address:        3645 Marine Street
City:           Boulder
StateProv:      CO
PostalCode:     80309-0455
Country:        US
RegDate:        1986-03-11
Updated:        2019-06-25
Ref:            https://rdap.arin.net/registry/entity/UNIVER-24


OrgTechHandle: CUBOU-ARIN
OrgTechName:   CUBoulder
OrgTechPhone:  +1-303-735-4357 
OrgTechEmail:  arinadmin@colorado.edu
OrgTechRef:    https://rdap.arin.net/registry/entity/CUBOU-ARIN

OrgAbuseHandle: ABUSE306-ARIN
OrgAbuseName:   Abuse
OrgAbusePhone:  +1-303-735-4357 
OrgAbuseEmail:  abuse@colorado.edu
OrgAbuseRef:    https://rdap.arin.net/registry/entity/ABUSE306-ARIN

RAbuseHandle: ABUSE306-ARIN
RAbuseName:   Abuse
RAbusePhone:  +1-303-735-4357 
RAbuseEmail:  abuse@colorado.edu
RAbuseRef:    https://rdap.arin.net/registry/entity/ABUSE306-ARIN

RTechHandle: CUBOU-ARIN
RTechName:   CUBoulder
RTechPhone:  +1-303-735-4357 
RTechEmail:  arinadmin@colorado.edu
RTechRef:    https://rdap.arin.net/registry/entity/CUBOU-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.
#

Source: whois.arin.netWHOIS.TD / LOOKUP
BULK EXPLORER

More names. One workspace.

One domain per line, up to 10. Results reflect lookup status, not registration availability.