Observed topology
AS2603 NORDUNET
Transit
Upstream networks
Networks observed carrying traffic for AS2603: the AS immediately before it in a routing path. Ranked by how many paths showed the relationship, which reflects how widely it is used, not how much traffic crosses it.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS1299 | Arelion Sweden AB | Transit | IPv4 IPv6 | 159 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 96 |
| AS34549 | meerfarbig GmbH & Co. KG | Hosting | IPv4 IPv6 | 44 |
| AS9002 | RETN Limited | Unclassified | IPv4 IPv6 | 31 |
| AS11537 | Internet2 | Unclassified | IPv4 | 24 |
| AS33891 | Core-Backbone GmbH | Hosting | IPv4 | 18 |
| AS4635 | Hong Kong Internet Exchange--Route Server 1 | Unclassified | IPv4 | 18 |
| AS50304 | Blix Solutions AS | Unclassified | IPv4 IPv6 | 14 |
| AS6830 | Liberty Global Europe Holding B.V. | Residential | IPv4 | 12 |
| AS1836 | green.ch AG | Residential | IPv4 IPv6 | 12 |
| AS48362 | Stadtwerke Feldkirch | Residential | IPv4 IPv6 | 12 |
| AS3491 | PCCW Global (HK) Ltd. | Transit | IPv4 IPv6 | 12 |
| AS3333 | Reseaux IP Europeens Network Coordination Centre (RIPE NCC) | Unclassified | IPv4 IPv6 | 12 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 12 |
| AS6762 | TELECOM ITALIA SPARKLE S.p.A. | Transit | IPv4 IPv6 | 12 |
| AS34019 | Hivane Association | Unclassified | IPv4 IPv6 | 11 |
| AS2497 | Internet Initiative Japan Inc. | Unclassified | IPv4 | 10 |
| AS37100 | SEACOM Limited | Unclassified | IPv4 | 10 |
| AS293 | ESnet | Unclassified | IPv4 | 10 |
| AS3741 | Dimension Data | Unclassified | IPv4 | 10 |
| AS6696 | VERIXI SA | Unclassified | IPv4 | 10 |
| AS42708 | Glesys AB | Unclassified | IPv4 | 10 |
| AS48185 | team.blue NV | Unclassified | IPv4 | 10 |
| AS20514 | Axians AB | Hosting | IPv4 | 10 |
| AS12389 | PJSC Rostelecom | Residential | IPv4 | 10 |
| AS56655 | Gigahost AS | Unclassified | IPv4 IPv6 | 10 |
| AS6461 | Zayo Bandwidth | Transit | IPv4 | 9 |
| AS3303 | Swisscom (Schweiz) AG | Residential | IPv4 | 9 |
| AS20965 | GEANT Vereniging | Unclassified | IPv4 IPv6 | 9 |
| AS7575 | Australian Academic and Research Network (AARNet) | Education | IPv4 IPv6 | 9 |
| AS852 | TELUS Communications Inc. | Residential | IPv4 IPv6 | 9 |
| AS14907 | Wikimedia Foundation Inc. | Hosting | IPv4 IPv6 | 9 |
| AS1273 | IDDQD-AS | Business | IPv4 IPv6 | 9 |
| AS49788 | Nexthop AS | Unclassified | IPv4 | 8 |
| AS2914 | NTT America, Inc. | Transit | IPv6 | 5 |
| AS20473 | The Constant Company, LLC | Hosting | IPv6 | 2 |
| AS12779 | IT.Gate S.p.A. | Unclassified | IPv4 | 1 |
| AS29169 | GANDI SAS | Hosting | IPv4 | 1 |
Inferred from path position, not from any declaration by either party. A network appearing here is carrying these routes; whether that is a paid transit arrangement, a backup, or something else is not something routing data can tell you.
Transit
Downstream networks
Networks for which AS2603 was observed as the last hop before the origin, meaning it appears to provide them transit.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS1653 | Vetenskapsradet / SUNET | Unclassified | IPv4 IPv6 | 2,540 |
| AS1741 | Tieteen tietotekniikan keskus Oy | Unclassified | IPv4 IPv6 | 1,974 |
| AS224 | Sikt - Kunnskapssektorens Tjenesteleverandor | Unclassified | IPv4 IPv6 | 1,035 |
| AS1835 | IDDQD-AS | Unclassified | IPv4 IPv6 | 334 |
| AS8674 | Netnod AB | Unclassified | IPv4 IPv6 | 313 |
| AS15474 | Rannsokna- og haskolanet Islands hf. | Unclassified | IPv4 IPv6 | 157 |
| AS2847 | Kauno Technologijos Universitetas | Education | IPv4 IPv6 | 148 |
| AS8501 | Institute of Bioorganic Chemistry Polish Academy of Science, Poznan Supercomputing and Networking Center | Education | IPv4 IPv6 | 142 |
| AS39590 | NORDUnet | Unclassified | IPv4 IPv6 | 83 |
| AS198093 | Foreningen for digitala fri- och rattigheter | Unclassified | IPv4 IPv6 | 58 |
| AS2832 | Vetenskapsradet / SUNET | Education | IPv4 IPv6 | 36 |
| AS3221 | Haridus- ja Teadusministeerium | Education | IPv4 IPv6 | 18 |
| AS21320 | GEANT Vereniging | Unclassified | IPv4 | 15 |
| AS6509 | CANARIE Inc | Education | IPv6 | 2 |
Adjacency
Adjacent networks
Every AS seen directly next to AS2603 in a routing path, in either direction.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS21320 | GEANT Vereniging | Unclassified | IPv4 IPv6 | 15,486 |
| AS1653 | Vetenskapsradet / SUNET | Unclassified | IPv4 IPv6 | 6,710 |
| AS34549 | meerfarbig GmbH & Co. KG | Hosting | IPv4 IPv6 | 4,750 |
| AS1299 | Arelion Sweden AB | Transit | IPv4 IPv6 | 3,506 |
| AS8501 | Institute of Bioorganic Chemistry Polish Academy of Science, Poznan Supercomputing and Networking Center | Education | IPv4 IPv6 | 2,722 |
| AS1741 | Tieteen tietotekniikan keskus Oy | Unclassified | IPv4 IPv6 | 2,496 |
| AS3741 | Dimension Data | Unclassified | IPv4 | 1,617 |
| AS224 | Sikt - Kunnskapssektorens Tjenesteleverandor | Unclassified | IPv4 IPv6 | 1,611 |
| AS20514 | Axians AB | Hosting | IPv4 | 1,456 |
| AS37100 | SEACOM Limited | Unclassified | IPv4 | 1,449 |
| AS50304 | Blix Solutions AS | Unclassified | IPv4 IPv6 | 1,418 |
| AS49788 | Nexthop AS | Unclassified | IPv4 | 1,407 |
| AS48362 | Stadtwerke Feldkirch | Residential | IPv4 IPv6 | 1,399 |
| AS42708 | Glesys AB | Unclassified | IPv4 | 1,389 |
| AS3333 | Reseaux IP Europeens Network Coordination Centre (RIPE NCC) | Unclassified | IPv4 IPv6 | 1,376 |
| AS6696 | VERIXI SA | Unclassified | IPv4 | 1,344 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 1,289 |
| AS56655 | Gigahost AS | Unclassified | IPv4 IPv6 | 1,199 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 977 |
| AS11537 | Internet2 | Unclassified | IPv4 IPv6 | 887 |
| AS1835 | IDDQD-AS | Unclassified | IPv4 IPv6 | 871 |
| AS8674 | Netnod AB | Unclassified | IPv4 IPv6 | 802 |
| AS34019 | Hivane Association | Unclassified | IPv4 IPv6 | 595 |
| AS14907 | Wikimedia Foundation Inc. | Hosting | IPv4 IPv6 | 580 |
| AS1836 | green.ch AG | Residential | IPv4 IPv6 | 556 |
| AS852 | TELUS Communications Inc. | Residential | IPv4 IPv6 | 507 |
| AS293 | ESnet | Unclassified | IPv4 | 468 |
| AS2497 | Internet Initiative Japan Inc. | Unclassified | IPv4 | 466 |
| AS48185 | team.blue NV | Unclassified | IPv4 | 430 |
| AS6762 | TELECOM ITALIA SPARKLE S.p.A. | Transit | IPv4 IPv6 | 427 |
| AS9002 | RETN Limited | Unclassified | IPv4 IPv6 | 417 |
| AS4635 | Hong Kong Internet Exchange--Route Server 1 | Unclassified | IPv4 IPv6 | 279 |
| AS7575 | Australian Academic and Research Network (AARNet) | Education | IPv4 IPv6 | 272 |
| AS2847 | Kauno Technologijos Universitetas | Education | IPv4 IPv6 | 261 |
| AS6461 | Zayo Bandwidth | Transit | IPv4 | 234 |
| AS15474 | Rannsokna- og haskolanet Islands hf. | Unclassified | IPv4 IPv6 | 218 |
| AS33891 | Core-Backbone GmbH | Hosting | IPv4 IPv6 | 211 |
| AS3491 | PCCW Global (HK) Ltd. | Transit | IPv4 IPv6 | 182 |
| AS20473 | The Constant Company, LLC | Hosting | IPv6 | 181 |
| AS12389 | PJSC Rostelecom | Residential | IPv4 | 175 |
| AS1273 | IDDQD-AS | Business | IPv4 IPv6 | 162 |
| AS6830 | Liberty Global Europe Holding B.V. | Residential | IPv4 | 149 |
| AS12552 | GlobalConnect AB | Unclassified | IPv4 | 121 |
| AS3303 | Swisscom (Schweiz) AG | Residential | IPv4 IPv6 | 111 |
| AS39590 | NORDUnet | Unclassified | IPv4 IPv6 | 83 |
| AS2914 | NTT America, Inc. | Transit | IPv6 | 61 |
| AS198093 | Foreningen for digitala fri- och rattigheter | Unclassified | IPv4 IPv6 | 58 |
| AS3221 | Haridus- ja Teadusministeerium | Education | IPv4 IPv6 | 55 |
| AS8434 | Telenor Sverige AB | Residential | IPv4 | 39 |
| AS2832 | Vetenskapsradet / SUNET | Education | IPv4 IPv6 | 36 |
| AS6509 | CANARIE Inc | Education | IPv6 | 33 |
| AS20965 | GEANT Vereniging | Unclassified | IPv4 IPv6 | 15 |
| AS29169 | GANDI SAS | Hosting | IPv4 | 12 |
| AS12779 | IT.Gate S.p.A. | Unclassified | IPv4 | 4 |
| AS31500 | Global Network Management Inc | Unclassified | IPv4 | 3 |
| AS1103 | SURF B.V. | Unclassified | IPv6 | 1 |
Adjacency is not the same as peering. Being next to each other in a path covers paid transit, settlement-free peering and customer connections alike, and routing data cannot distinguish them. Treat this as "these networks exchange routes", nothing more specific.
Interconnection
Exchange presence
Internet exchanges where Packet Clearing House has a port recorded for AS2603, largest fabric first. An exchange is shared switching where networks interconnect directly rather than paying a transit provider to carry traffic between them, so turning up at one is a deliberate choice about how this network wants to be reached. Each name opens that exchange's own page, with its peering LANs and every other network recorded on it. Recorded at 24 exchanges across 14 countries and 3 regions.
| Exchange | Location | Their address | Member ports |
|---|---|---|---|
| DE-CIX Frankfurt | Frankfurt, Germany | 80.81.192.241 | 1,073 |
| LINX LON1 | London, United Kingdom | 195.66.225.24 | 925 |
| AMS-IX Amsterdam | Amsterdam, Netherlands | 80.249.209.203 | 894 |
| Neutral Internet Exchange | Amsterdam, Netherlands | 193.239.116.53 | 665 |
| Equinix Internet Exchange Ashburn | Ashburn, United States | 206.126.236.230 | 388 |
| London Network Access Point | London, United Kingdom | 5.57.80.168 | 316 |
| Hong Kong Internet Exchange | Hong Kong, China | 123.255.91.213 | 307 |
| Equinix Internet Exchange Chicago | Chicago, United States | 208.115.136.151 | 280 |
| Singapore Internet Exchange | Singapore, Singapore | 103.16.102.155 | 273 |
| JPIX Tokyo | Tokyo, Japan | 210.171.225.238 | 259 |
| New York International Internet Exchange | New York, United States | 198.32.160.21 | 217 |
| Internet Neutral Exchange Association CLG - LAN1 | Dublin, Ireland | 185.6.36.167 | 115 |
| Megaport Frankfurt IX | Frankfurt, Germany | 62.69.146.103 | 114 |
| Sweden Open Network Internet eXchange Stockholm | Stockholm, Sweden | 185.1.215.80 | 97 |
| STHIX - Stockholm | Stockholm, Sweden | 192.121.80.45 | 91 |
| Stockholm Internet Exchange | Stockholm, Sweden | 192.121.80.45 | 91 |
| Norwegian Internet Exchange Oslo 1 | Oslo, Norway | 185.1.55.5 | 70 |
| Megaport Hamburg IX | Hamburg, Germany | 193.42.155.67 | 62 |
| CERN IXP / Equinix Internet Exchange Geneva | Geneva, Switzerland | 192.65.185.132 | 54 |
| Reykjavik Internet Exchange | Reykjavik, Iceland | 195.130.211.12 | 30 |
| Asteroid Amsterdam IX | Amsterdam, Netherlands | 185.1.94.20 | 27 |
| Tampere Region Exchange | Tampere, Finland | 195.140.192.15 | 27 |
| STHIX - Copenhagen | Copenhagen, Denmark | 185.1.88.18 | 21 |
| Netnod Sundsvall- Gävle | Sundsvall, Sweden | 194.68.128.24 | 18 |
Unlike the tables above, this is recorded rather than inferred. An address on a peering LAN is at that exchange by definition. Two carve-outs all the same. Member ports counts every participant at the exchange, not this network's ports, so read it as a size proxy. And an absent exchange means PCH has no record of it, not that the network is not there.
Provenance
Where this comes from
Derived from routing tables collected at 2026-08-08 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.02M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.
Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.
Exchange presence comes from a separate dataset: the directory collected 2026-08-09 by Packet Clearing House (https://www.pch.net/ixp/data), covering 1,327 exchanges and 93,164 recorded member ports, licensed CC BY-NC-SA 3.0.
PeeringDB is the better-known directory and is deliberately not the source here: its acceptable-use policy forbids the bulk storage this needs. The two answer different questions anyway. PeeringDB reports what an operator declares about itself; this reports what PCH has recorded.