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Autonomous System

AS21320 · GEANT Vereniging

Overview

AS21320 is announced on the Internet: RIPE RIS route collectors currently see 1 IPv4 prefix and no IPv6 prefix originated by this network. Together, its IPv4 prefixes cover 2,048 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 23 upstream neighbours (transit providers or peers) and 149 downstream neighbours (customers or networks it carries). Its most visible upstreams are NORDUnet (AS2603), Cogent Communications, LLC (AS174), and Level 3 Parent, LLC (AS3356). AS21320 was assigned by RIPE NCC, and its registration country is Netherlands.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 16, 2026 at 8:03 PM UTC. This page is refreshed at most every 12 hours.

Go further

Trace a route to this networkOpen in the BGP viewerWHOIS of 83.97.88.1

The trace goes to 83.97.88.1, the first address of 83.97.88.0/21. 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 (1 prefix)

PrefixAddresses
83.97.88.0/212,048

IPv6 prefixes (none)

None currently seen.

Neighbours

Upstreams (transit or peers) (23)

ASNetworkVisibility
AS2603NORDUnet16,443
AS174Cogent Communications, LLC3,902
AS3356Level 3 Parent, LLC3,654
AS6939Hurricane Electric LLC2,757
AS9002RETN Limited1,636
AS1853ACOnet - ACONET1,182
AS13030Init7 (Switzerland) Ltd.1,137
AS6461Zayo Bandwidth1,020
AS33891Core-Backbone GmbH609
AS24961WIIT AG478
AS8218-363
AS5405Inter.link GmbH345
AS3303Swisscom (Schweiz) AG262
AS3216-256
AS30844Liquid Telecommunications Ltd215
AS8220COLT Technology Services Group Limited153
AS31133PJSC MegaFon131
AS9009M247 Europe SRL58
AS8966EMIRATES TELECOMMUNICATIONS GROUP COMPANY (ETISALAT GROUP) PJSC43
AS5400British Telecommunications Limited15
AS1103SURF B.V.9
AS6910DIGI ROMANIA S.A.2
AS8708DIGI ROMANIA S.A.1

Downstreams (customers) (149)

ASNetworkVisibility
AS6939Hurricane Electric LLC12,651
AS6461Zayo Bandwidth11,065
AS5408National Infrastructures for Research and Technology S.A.10,488
AS9002RETN Limited6,907
AS766RedIRIS Entidad Publica Empresarial Red.es3,249
AS2200Renater2,939
AS1930Fundacao para a Ciencia e a Tecnologia, I.P.1,845
AS31133PJSC MegaFon1,766
AS3216PJSC "Vimpelcom"1,725
AS1853ACOnet - ACONET1,582
AS8517-1,435
AS33891Core-Backbone GmbH1,336
AS1955-1,276
AS5405Inter.link GmbH1,211
AS8220COLT Technology Services Group Limited1,187
AS2614RoEduNet Agentia de Administrare a Retelei Nationale de Informatica pentru Educatie si Cercetare1,179
AS8501Institute of Bioorganic Chemistry Polish Academy of Science, Poznan Supercomputing and Networking Center1,059
AS136968SingAREN1,042
AS2852CESNET z.s.p.o.963
AS13092-878
AS2107-726
AS6802Bulgarian Research and Education Network Association (BREN)716
AS12687-704
AS30844Liquid Telecommunications Ltd700
AS2611BELNET660
AS3268-612
AS378-603
AS12046-602
AS44224-595
AS4134No.31,Jin-rong Street529

The 30 most visible of 149.

50 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.