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Autonomous System

AS204921 ยท zhenyun sun

Overview

AS204921 is announced on the Internet: RIPE RIS route collectors currently see 6 IPv4 prefixes and 17 IPv6 prefixes originated by this network. Together, its IPv4 prefixes cover 1,024 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 22 upstream neighbours (transit providers or peers) and 2 downstream neighbours (customers or networks it carries). Its most visible upstreams are The Constant Company, LLC (AS20473), Hop179 OU (AS11967), and MoeDove LLC (AS44324). AS204921 was assigned by RIPE NCC, and its registration country is United Kingdom.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 17, 2026 at 1:34 AM UTC. This page is refreshed at most every 12 hours.

Go further

The trace goes to 177.177.80.1, the first address of 177.177.80.0/22. 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 (6 prefixes)

PrefixAddresses
177.177.80.0/221,024
177.177.80.0/23512
177.177.80.0/24256
177.177.81.0/24256
177.177.82.0/23512
177.177.83.0/24256

IPv6 prefixes (17 prefixes)

Prefix
2602:f3ff:83::/48
2a0e:aa07:e250::/44
2a0e:aa07:e251::/48
2a0e:aa07:e252::/48
2a0e:aa07:e253::/48
2a0e:aa07:e256::/48
2a0e:aa07:e25b::/48
2a12:cb41:801::/48
2a12:cb41:802::/48
2a12:cb41:803::/48
2a12:cb41:804::/48
2a12:cb41:805::/48
2a12:cb41:806::/48
2a12:cb41:809::/48
2a12:cb41:80a::/48
2a12:cb41:80b::/48
2a12:cb41:80c::/48

Neighbours

Upstreams (transit or peers) (22)

ASNetworkVisibility
AS20473The Constant Company, LLC510
AS11967Hop179 OU487
AS44324MoeDove LLC422
AS199310XIN BING XIAN390
AS18423RAID Networks Co., Ltd.372
AS36530IDC Cube340
AS140096JINX CO., LIMITED278
AS204539Axivora Connect Ltd260
AS204211Shanghai Yingyun Network Technology Co., Ltd.259
AS216211CYBERVERSE LLC244
AS6939Hurricane Electric LLC224
AS51087-221
AS40792-10
AS25091IP-Max SA7
AS17408-6
AS34549meerfarbig GmbH & Co. KG3
AS8298IPng Networks GmbH2
AS10133-1
AS11421-1
AS31500Global Network Management Inc1
AS48646SDRmedia Verwaltungs GmbH1
AS401753-1

Downstreams (customers) (2)

ASNetworkVisibility
AS208223SHU-HAO TUNG253
AS6939Hurricane Electric LLC3

18 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.