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Autonomous System

AS237 · Merit Network Inc.

Overview

AS237 is announced on the Internet: RIPE RIS route collectors currently see 83 IPv4 prefixes and 9 IPv6 prefixes originated by this network. Together, its IPv4 prefixes cover 2,221,568 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 9 upstream neighbours (transit providers or peers) and 34 downstream neighbours (customers or networks it carries). Its most visible upstreams are Arelion Sweden AB (AS1299), Cogent Communications, LLC (AS174), and NTT America, Inc. (AS2914). AS237 was assigned by ARIN, and its registration country is United States.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 16, 2026 at 8:57 PM UTC. This page is refreshed at most every 12 hours.

Go further

Trace a route to this networkOpen in the BGP viewerWHOIS of 35.64.0.1

The trace goes to 35.64.0.1, the first address of 35.64.0.0/14. An address picked inside a prefix may not answer (nothing listens there, or the network filters probes): the trace then shows the path up to the last network that replies.

Announced prefixes

IPv4 prefixes (83 prefixes)

PrefixAddresses
23.135.208.0/24256
35.16.0.0/1665,536
35.24.0.0/1732,768
35.24.128.0/1816,384
35.24.192.0/198,192
35.24.224.0/198,192
35.25.0.0/1665,536
35.33.0.0/1816,384
35.33.5.0/24256
35.33.6.0/24256
35.33.96.0/198,192
35.34.0.0/1816,384
35.37.0.0/1665,536
35.38.0.0/1665,536
35.39.0.0/198,192
35.39.32.0/198,192
35.39.64.0/198,192
35.39.128.0/198,192
35.39.160.0/198,192
35.39.192.0/198,192
35.39.224.0/198,192
35.40.0.0/1665,536
35.46.0.0/1816,384
35.46.64.0/1816,384
35.50.0.0/1732,768
35.50.0.0/1816,384
35.50.64.0/1816,384
35.58.0.0/1665,536
35.62.0.0/1665,536
35.63.0.0/1665,536
35.64.0.0/14262,144
35.68.0.0/15131,072
35.70.0.0/1665,536
35.71.0.0/1816,384
74.115.236.0/23512
74.115.236.0/24256
74.115.237.0/24256
141.210.0.0/1665,536
141.210.0.0/1732,768
141.210.32.0/198,192
141.210.128.0/1732,768
141.210.224.0/198,192
141.217.0.0/1665,536
141.218.0.0/1665,536
141.218.11.0/24256
141.218.203.0/24256
141.218.204.0/221,024
141.218.208.0/204,096
141.218.224.0/221,024
141.218.228.0/23512
148.61.0.0/1665,536
161.133.0.0/1732,768
161.133.2.0/24256
161.133.104.0/212,048
161.133.112.0/212,048
161.133.120.0/212,048
161.133.128.0/1732,768
161.133.129.0/24256
163.253.36.0/221,024
164.76.0.0/1665,536
164.76.160.0/198,192
192.35.170.0/24256
192.41.229.0/24256
192.41.232.0/221,024
192.88.242.0/24256
192.122.182.0/23512
192.122.184.0/212,048
192.122.200.0/24256
192.138.137.0/24256
192.160.192.0/24256
192.160.204.0/24256
192.188.100.0/24256
192.203.195.0/24256
192.245.252.0/24256
192.245.254.0/24256
198.17.130.0/23512
198.17.132.0/23512
198.108.0.0/14262,144
204.38.0.0/1665,536
204.39.195.0/24256
206.201.157.0/24256
207.72.0.0/14262,144
207.75.164.0/23512

IPv6 prefixes (9 prefixes)

Prefix
2001:468:2620::/48
2001:468:26e1::/48
2001:48a8::/32
2001:48a8:800::/40
2001:48a8:68fe::/48
2001:48a8:7800::/40
2606:9700::/32
2607:ff30:1110::/48
2620:13f:6000::/44

Neighbours

Upstreams (transit or peers) (9)

ASNetworkVisibility
AS1299Arelion Sweden AB3,001
AS174Cogent Communications, LLC1,982
AS2914NTT America, Inc.1,468
AS6939Hurricane Electric LLC886
AS11537Internet2202
AS11164Internet2201
AS3303Swisscom (Schweiz) AG173
AS7018AT&T Enterprises, LLC103
AS293ESnet32

Downstreams (customers) (34)

ASNetworkVisibility
AS231Michigan State University644
AS36375University of Michigan548
AS46825Coldwater Board of Public Utilities366
AS27274Central Michigan University364
AS229Merit Network Inc.356
AS11206Ferris State University314
AS396470Lansing Community College276
AS62618Michigan Technological University269
AS62676University of Michigan - Dearborn265
AS402639Washtenaw262
AS1638-260
AS14924-260
AS26174-260
AS46241-260
AS394769-260
AS400927-260
AS393817-258
AS22217-257
AS177-247
AS15099-247
AS1432-237
AS22251-227
AS19106-199
AS11494Kellogg Community College150
AS25609-139
AS32285-72
AS398261-64
AS393665-42
AS400238-42
AS3730-37

The 30 most visible of 34.

2 more neighbours appear on both sides of this network depending on the path, so they are counted in neither list.

Visibility is RIPEstat's count of how often the route collectors observed the link. It compares neighbours with each other; it is not a traffic volume.

How to read this page

An Autonomous System (AS) is a network run under one routing policy: an internet provider, a cloud, a content network, a university. Each one has a number, its ASN, assigned by a regional registry (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC), and uses BGP, the protocol networks use to tell each other where addresses are, to announce the blocks of addresses it delivers to.

A prefix such as 203.0.113.0/24 is a block of addresses: the number after the slash says how many bits are fixed, so a /24 holds 256 IPv4 addresses and a /16 holds 65,536. Networks often announce a large block and smaller pieces of it at the same time, which is why the address total counts each address once.

Neighbours come from the paths themselves. A network that appears just before this one in a path, on the collector's side, is an upstream: a transit provider or a peer. One that appears just after it is a downstream, usually a customer. Peering at an internet exchange also shows up as an upstream, so the upstream list is not a list of paid transit.

The data comes from RIPEstat, run by the RIPE NCC, which gathers the routing tables of hundreds of networks through its RIS route collectors. This page reads it when it is visited and keeps it for 12 hours at most; the BGP viewer reads it live.

Frequently asked questions

How do I find the ASN of an IP address?
Type the address in the BGP viewer: it shows the prefix that covers it, the AS that originates that prefix and the paths seen towards it. A traceroute also names the network of each hop, so you can see every AS a connection crosses.
Why does one company have several ASNs?
Large operators split their network by region, by activity or by history: a cloud may use one number for its backbone and another for a region, and every acquisition brings its own numbers. Each number has its own page, with its own prefixes and neighbours.
Why do prefix counts differ from one site to another?
Each source sees the routing table from different collectors, at a different time, and counts differently: some include prefixes withdrawn in recent weeks, some merge a block and its pieces. This page counts the prefixes RIPE RIS collectors see originated by the network at the end of the latest two-week window, and counts each IPv4 address once.
Is this the list of IP ranges of a cloud provider?
It is what its networks announce, which is what the Internet routes to them. Many providers also publish an official list of ranges per service and region; that list is the reference for firewall rules, because a range can be announced before it is used, or announced by another of their AS numbers.