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AS3128University of Wisconsin System

United StatesRegistryARIN

As of 22nd October 2026, AS3128 (University of Wisconsin System), a network registered in the United States with ARIN, originates 12 IPv4 prefixes covering 657k addresses and 1 IPv6 prefix. By IPv4 address space that makes it the 602nd-largest of the 79,663 networks we see originating IPv4, and the 146th-largest of 18,476 in the United States. It is seen behind 6 upstream networks, most often AS2381 (WiscNet) and AS1299 (Arelion (fka. Telia Carrier)), and in front of 6 downstream networks. Every one of its announcements has a valid RPKI ROA, and none are RPKI-invalid. 100% of its routes reach at least 90% of full-feed peers.

At a glance

IPv4 prefixes

12

IPv6 prefixes

1

IPv4 addresses

657k

IPv6 /64s

68.7B

Upstream graph

The networks AS3128 is seen behind, one and two hops out, drawn from real AS paths.

AS3128Toward the internet core
Upstream graph for AS3128: 12 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS3128University of Wis…This networkAS1299Arelion (fka. Tel…AS2381WiscNetAS6939Hurricane Electri…AS7018AT&T Enterprises,…AS11164Internet2 I2PXAS13030Init7 (Switzerlan…AS16552Tiggee LLCAS20130Depaul UniversityAS132337AxclusiveAS3356Lumen (Level 3)AS2152CENIC - CalRENAS2497Internet Initiati…

Networks observed one and two hops upstream of AS3128 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.

Neighbouring networks

29

adjacent networks

Upstreams
621%
Peers
1759%
Downstreams
621%

Networks carrying this one's traffic toward the rest of the internet.

Upstreams of AS3128
NetworkCountryRelationshipPathsVantage pts
AS2381WiscNetUSPeer1,44743
AS1299Arelion (fka. Telia Carrier)SEPeer1,10239
AS6939Hurricane Electric LLCUSPeer30762
AS11164Internet2 I2PXUSPeer2659
AS7018AT&T Enterprises, LLCUSPeer1064
AS11537Internet2USPeer632

Prefixes

The largest blocks AS3128 originates, widest first.

Largest prefixes originated by AS3128
PrefixAddressesVisibility
131.210.0.0/1665.5k77/77
137.81.0.0/1665.5k77/77
137.104.0.0/1665.5k77/77
138.49.0.0/1665.5k77/77
139.225.0.0/1665.5k77/77
141.233.0.0/1665.5k77/77
143.200.0.0/1665.5k77/77
143.235.0.0/1665.5k77/77
143.236.0.0/1665.5k77/77
144.13.0.0/1665.5k77/77

Routing health

How AS3128's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.

RPKI origin validation

  • Valid100.0%13
  • Invalid0.0%0
  • No ROA0.0%0

Propagation

  • Globally propagated90% of full-feed peers or more100.0%13
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 12 prefixes

IPv6 — 1 prefixes

  • /2868.7B × /64100.0%1

Recent changes

Announcements that started or stopped since 23rd Sept 2026.

No announcement by AS3128 started or stopped in this period.

Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.