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Autonomous System

AS2603 · NORDUnet

Overview

AS2603 is announced on the Internet: RIPE RIS route collectors currently see 10 IPv4 prefixes and 2 IPv6 prefixes originated by this network. Together, its IPv4 prefixes cover 9,728 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 76 upstream neighbours (transit providers or peers) and 34 downstream neighbours (customers or networks it carries). Its most visible upstreams are Arelion Sweden AB (AS1299), TELECOM ITALIA SPARKLE S.p.A. (AS6762), and Hurricane Electric LLC (AS6939). AS2603 was assigned by RIPE NCC, and its registration country is Denmark.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 16, 2026 at 8:58 PM UTC. This page is refreshed at most every 12 hours.

Go further

The trace goes to 109.105.96.1, the first address of 109.105.96.0/20. 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 (10 prefixes)

PrefixAddresses
109.105.96.0/204,096
109.105.112.0/212,048
109.105.120.0/221,024
185.174.116.0/221,024
192.36.171.0/24256
193.10.252.0/24256
193.10.254.0/24256
193.10.255.0/24256
193.11.3.0/24256
194.68.13.0/24256

IPv6 prefixes (2 prefixes)

Prefix
2001:948::/29
2001:948::/32

Neighbours

Upstreams (transit or peers) (76)

ASNetworkVisibility
AS1299Arelion Sweden AB2,759
AS6762TELECOM ITALIA SPARKLE S.p.A.2,217
AS6939Hurricane Electric LLC1,668
AS34549meerfarbig GmbH & Co. KG1,293
AS25091IP-Max SA1,211
AS3491PCCW Global (HK) Ltd.1,021
AS6777Amsterdam Internet Exchange B.V.828
AS48362Stadtwerke Feldkirch696
AS50304Blix Solutions AS639
AS6461Zayo Bandwidth635
AS9002RETN Limited617
AS34177Celeste SAS574
AS61049Exascale Ltd549
AS34019Hivane Association534
AS20764CJSC RASCOM520
AS2914NTT America, Inc.489
AS21320GEANT Vereniging481
AS4635Hong Kong Internet Exchange--Route Server 1459
AS41327Fiber Telecom S.p.A.422
AS50629LWLcom GmbH418
AS6730-401
AS28716-362
AS29075IELO-LIAZO SERVICES SAS339
AS33891Core-Backbone GmbH338
AS35280F5 Networks SARL338
AS6696-330
AS42708Glesys AB329
AS12779-327
AS13030Init7 (Switzerland) Ltd.309
AS56655Gigahost AS285

The 30 most visible of 76.

Downstreams (customers) (34)

ASNetworkVisibility
AS21320GEANT Vereniging16,133
AS1653Vetenskapsradet / SUNET8,037
AS8501Institute of Bioorganic Chemistry Polish Academy of Science, Poznan Supercomputing and Networking Center4,155
AS1835IDDQD-AS2,057
AS1741CSC - Tieteen tietotekniikan keskus Oy2,009
AS224Sikt - Kunnskapssektorens Tjenesteleverandor1,824
AS8674Netnod AB1,109
AS15474Rannsokna- og haskolanet Islands hf.614
AS39590NORDUnet363
AS3221Haridus- ja Teadusministeerium336
AS2832-242
AS2847-212
AS198093-139
AS3301-110
AS6509CANARIE Inc72
AS6461Zayo Bandwidth18
AS39889Fredrik Holmqvist8
AS20514-5
AS48685-4
AS30818-3
AS30880-3
AS1850-2
AS12969-2
AS13335Cloudflare, Inc.2
AS24743-2
AS25509-2
AS29689-2
AS44275-2
AS51896-2
AS42WoodyNet, Inc.1

The 30 most visible of 34.

59 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.