AS3128
University of Wisconsin System
Reputation · trust score
A transparent 0–100 signal. Every entity starts at a neutral baseline of 65; threat-intel blocklists, exposure, reverse-DNS, routing and allocation each adjust it up or down. Higher is more trustworthy.
- Baseline (neutral) 65
- Academic allocation +6
- Trust score 71 / 100
Experimental · trust-vectors model v1.1.0 — a transparent heuristic, not a definitive verdict. How it works →
Network profile
Source: PeeringDB →Present at 3 internet exchanges: MadIX, MICE: Shared Peering, MKE-IX
AS3128 — global IP footprint
Cities where AS3128 has measurable IPv4 allocation. Click any dot to open that city's page. Size and color scale with IP count.
Top CIDR ranges
| CIDR | IPs | PTR Density | Organization | Country | State | City |
|---|---|---|---|---|---|---|
| 131.210.0.0/16 | 65.5K |
0.0%
|
University of Wisconsin System | US | Wisconsin | Kenosha |
| 137.81.0.0/16 | 65.5K |
0.3%
|
University of Wisconsin System | US | Wisconsin | Superior |
| 137.104.0.0/16 | 65.5K |
9.6%
|
University of Wisconsin System | US | Wisconsin | Franklin |
| 138.49.0.0/16 | 65.5K |
0.4%
|
University of Wisconsin System | US | Wisconsin | La Crosse |
| 139.225.0.0/16 | 65.5K |
0.0%
|
University of Wisconsin System | US | Wisconsin | River Falls |
| 141.233.0.0/16 | 65.5K |
0.4%
|
University of Wisconsin System | US | Wisconsin | Oshkosh |
| 143.200.0.0/16 | 65.5K |
0.1%
|
University of Wisconsin System | US | Wisconsin | Green Bay |
| 143.235.0.0/16 | 65.5K |
0.3%
|
University of Wisconsin System | US | Wisconsin | Madison |
| 143.236.0.0/16 | 65.5K |
0.3%
|
University of Wisconsin System | US | Wisconsin | Stevens Point |
| 144.13.0.0/16 | 65.5K |
0.0%
|
University of Wisconsin System | US | Wisconsin | Menomonie |
| 192.35.81.0/24 | 256 |
0.0%
|
University of Wisconsin System | US | — | — |
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS3128 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.
| Prefix | Announcement samples | Last seen |
|---|---|---|
| 138.49.160.0/22 | 11,248 | 2026-07-22 23:47:26 |
| 139.225.0.0/16 | 7,673 | 2026-07-22 23:47:26 |
| 131.210.0.0/16 | 7,189 | 2026-07-22 23:47:26 |
| 137.104.0.0/16 | 6,841 | 2026-07-22 23:47:26 |
| 143.235.0.0/16 | 6,812 | 2026-07-22 23:47:26 |
| 141.233.0.0/16 | 6,024 | 2026-07-22 23:47:26 |
| 143.236.0.0/16 | 5,895 | 2026-07-22 23:47:26 |
| 143.200.0.0/16 | 5,677 | 2026-07-22 23:47:26 |
| 144.13.0.0/16 | 5,645 | 2026-07-22 23:47:26 |
| 137.81.0.0/16 | 5,482 | 2026-07-22 23:47:26 |
| 138.49.0.0/16 | 5,394 | 2026-07-22 23:47:26 |
| 192.35.81.0/24 | 5,318 | 2026-07-22 23:47:26 |
| 143.235.33.0/24 | 2,282 | 2026-06-15 19:57:38 |
| 144.92.103.0/24 | 1,973 | 2026-06-04 17:13:38 |
Frequently Asked Questions
What is AS3128?
AS3128 is an Autonomous System Number assigned to University of Wisconsin System. An ASN identifies a network that controls a specific set of IP addresses and determines how traffic is routed across the internet via BGP (Border Gateway Protocol).
How many IP addresses does AS3128 announce?
AS3128 announces 655.6K IPv4 addresses distributed across 11 routed CIDR prefixes. The network is registered in United States.
Who operates AS3128?
AS3128 is operated by University of Wisconsin System. The organization is based in United States. You can view all IP ranges and related ASNs on the organization page.
What country is AS3128 registered in?
AS3128 is registered in United States. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
