AS104

University of Colorado at Boulder

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Summary

IP address summary information
Name	University of Colorado at Boulder
Country	United States
Website	host.io/colorado.edu·colorado.edu
Hosted domains	78
IPv4 addresses	91,136
IPv6 addresses	7.92 × 10²⁸
ASN type	Education
Registry	ARIN
Allocated	39 years ago on Apr 9, 1987
Updated	6 years ago on Jun 25, 2019

IP Ranges

Netblock	Company	Num of IPs
128.138.0.0/16	University of Colorado at Boulder	65,536
129.19.192.0/18	University of Colorado at Boulder	16,384
198.11.16.0/20	University of Colorado at Boulder	4,096
146.5.20.0/22	University of Colorado at Boulder	1,024
192.12.238.0/24	University of Colorado at Boulder	256
192.12.240.0/24	University of Colorado at Boulder	256
192.12.241.0/24	University of Colorado at Boulder	256
192.12.242.0/24	University of Colorado at Boulder	256
192.12.244.0/24	University of Colorado at Boulder	256
192.12.245.0/24	University of Colorado at Boulder	256

IP Ranges

WHOIS


  ASHandle:       █████
  OrgID:          █████
  ASName:         ██████
  ASNumber:       AS█████
  RegDate:        ████-██-██
  Updated:        ████-██-██
  TechHandle:     ████-████
  Source:         ████

Hosted Domains

There are 78 domain names hosted across 36 IP addresses on this ASN.

IP Address	Domain	Count
128.138.68.45		13
128.138.135.43		9
128.138.136.14		9
128.138.136.36		4
128.138.29.28		3

Peers

There are 2 peers for this ASN.

ASN	Name
AS3356	Level 3 Parent, LLC
AS14041	University Corporation for Atmospheric Research

Upstreams

There are 2 upstreams for this ASN.

ASN	Name
AS3356	Level 3 Parent, LLC
AS14041	University Corporation for Atmospheric Research

Downstreams

There are 0 downstreams for this ASN.

No downstreams found.

Pingable IPs

19 IPs in this ASN replied to an ICMP ping during our most recent internet scan. Learn more

IP Address	ASN	Details
198.59.55.10 Ping	AS104 University of Colorado at Boulder	0.62ms from Denver, US
128.138.141.162 Ping	AS104 University of Colorado at Boulder	1.92ms from Denver, US
128.138.232.65 Ping	AS104 University of Colorado at Boulder	1.51ms from Denver, US
2620:18f:30:1000::2 Ping	AS104 University of Colorado at Boulder	1.21ms from Denver, US
192.12.244.2 Ping	AS104 University of Colorado at Boulder	1.01ms from Denver, US
128.138.131.26 Ping	AS104 University of Colorado at Boulder	2.12ms from Denver, US
192.12.242.1 Ping	AS104 University of Colorado at Boulder	1.08ms from Denver, US
128.138.82.254 Ping	AS104 University of Colorado at Boulder	1.13ms from Denver, US
128.138.138.121 Ping	AS104 University of Colorado at Boulder	1.65ms from Denver, US
128.138.81.197 Ping	AS104 University of Colorado at Boulder	1.18ms from Denver, US

Other Pingable IPs

IP Address	ASN	Details

Pingable IPs

Important routers in AS104


128.138.81.11	Denver,United States
128.138.81.77	Denver,United States
198.59.55.118	Denver,United States
198.59.55.9	Denver,United States
128.138.81.15	Denver,United States
128.138.184.1	Denver,United States
128.138.81.253	Denver,United States
128.138.129.1	Denver,United States
128.138.81.254	Denver,United States
128.138.81.13	Denver,United States

Important routers in AS104

Traceroute

Below is a recent traceroute taken from the IPinfo ProbeNet to an IP in this ASN. Learn more.Traceroute →

$ traceroute -a -n -q1 -f3 128.138.210.16

traceroute to 128.138.210.16 (128.138.210.16): 64 hops max, 52 byte packets

3 [AS14041] 192.43.217.137 0.403 ms

4 [AS104] 198.59.55.9 1.254 ms

5 [AS104] 128.138.81.194 2.693 ms

6 [AS104] 128.138.81.249 1.436 ms

7 [AS104] 128.138.81.131 1.449 ms

8 [AS104] 128.138.81.75 1.476 ms

9 [AS104] 128.138.210.16 2.069 ms

Measurement taken from

IPinfo ProbeNet in Denver, US

On May 4, 2026

What is an ASN?

Autonomous System Numbers (ASNs) are assigned to entities such as Internet Service Providers and other large organizations that control blocks of IP addresses. This network page, and the organization field that's shown on the main IP address information page and also returned in the geolocation API are based on the ASN.

The ASN details will often correspond to the IP address owner, but for smaller organizations it may be that organization's parent, or their ISP. Find out more about AS104 at robtex.

AS104

Summary

IP Ranges

IP Ranges

WHOIS

Hosted Domains

Peers

Upstreams

Downstreams

Pingable IPs

Other Pingable IPs

Pingable IPs

Important routers in AS104

Important routers in AS104

Traceroute

AS10858

AS11834

AS16754

AS17071

AS30674

AS397146

What is an ASN?

An API built with users in mind: reliable, accurate, and easy-to-use

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Summarize IPs

Traceroute

Pingable IPs

Other Pingable IPs

IP Ranges

Important routers in AS104

AS10858

AS11834

AS16754

AS17071

AS30674

AS397146

AS104

Summary

IP Ranges

IP Ranges

WHOIS

Hosted Domains

Peers

Upstreams

Downstreams

Pingable IPs

Other Pingable IPs

Pingable IPs

Important routers in AS104

Important routers in AS104

Traceroute

Related Networks

AS10858

AS11834

AS16754

AS17071

AS30674

AS397146

What is an ASN?

An API built with users in mind: reliable, accurate, and easy-to-use

Our IP tools

What is my IP?

Map IPs

Summarize IPs

Traceroute

Pingable IPs

Other Pingable IPs

IP Ranges

Important routers in AS104

AS10858

AS11834

AS16754

AS17071

AS30674

AS397146