asn.dev

Observed topology

AS2603 NORDUNET

Upstreams 38 carry this network
Downstreams 14 this network carries
Adjacent (IPv4) 52
Adjacent (IPv6) 39

Transit

Upstream networks

inferred

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.

ASNetworkTypeFamiliesPaths seen
AS1299Arelion Sweden ABTransitIPv4 IPv6159
AS6939Hurricane Electric LLCTransitIPv4 IPv696
AS34549meerfarbig GmbH & Co. KGHostingIPv4 IPv644
AS9002RETN LimitedUnclassifiedIPv4 IPv631
AS11537Internet2UnclassifiedIPv424
AS33891Core-Backbone GmbHHostingIPv418
AS4635Hong Kong Internet Exchange--Route Server 1UnclassifiedIPv418
AS50304Blix Solutions ASUnclassifiedIPv4 IPv614
AS6830Liberty Global Europe Holding B.V.ResidentialIPv412
AS1836green.ch AGResidentialIPv4 IPv612
AS48362Stadtwerke FeldkirchResidentialIPv4 IPv612
AS3491PCCW Global (HK) Ltd.TransitIPv4 IPv612
AS3333Reseaux IP Europeens Network Coordination Centre (RIPE NCC)UnclassifiedIPv4 IPv612
AS24482SG.GSHostingIPv4 IPv612
AS6762TELECOM ITALIA SPARKLE S.p.A.TransitIPv4 IPv612
AS34019Hivane AssociationUnclassifiedIPv4 IPv611
AS2497Internet Initiative Japan Inc.UnclassifiedIPv410
AS37100SEACOM LimitedUnclassifiedIPv410
AS293ESnetUnclassifiedIPv410
AS3741Dimension DataUnclassifiedIPv410
AS6696VERIXI SAUnclassifiedIPv410
AS42708Glesys ABUnclassifiedIPv410
AS48185team.blue NVUnclassifiedIPv410
AS20514Axians ABHostingIPv410
AS12389PJSC RostelecomResidentialIPv410
AS56655Gigahost ASUnclassifiedIPv4 IPv610
AS6461Zayo BandwidthTransitIPv49
AS3303Swisscom (Schweiz) AGResidentialIPv49
AS20965GEANT VerenigingUnclassifiedIPv4 IPv69
AS7575Australian Academic and Research Network (AARNet)EducationIPv4 IPv69
AS852TELUS Communications Inc.ResidentialIPv4 IPv69
AS14907Wikimedia Foundation Inc.HostingIPv4 IPv69
AS1273IDDQD-ASBusinessIPv4 IPv69
AS49788Nexthop ASUnclassifiedIPv48
AS2914NTT America, Inc.TransitIPv65
AS20473The Constant Company, LLCHostingIPv62
AS12779IT.Gate S.p.A.UnclassifiedIPv41
AS29169GANDI SASHostingIPv41

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

inferred

Networks for which AS2603 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS1653Vetenskapsradet / SUNETUnclassifiedIPv4 IPv62,540
AS1741Tieteen tietotekniikan keskus OyUnclassifiedIPv4 IPv61,974
AS224Sikt - Kunnskapssektorens TjenesteleverandorUnclassifiedIPv4 IPv61,035
AS1835IDDQD-ASUnclassifiedIPv4 IPv6334
AS8674Netnod ABUnclassifiedIPv4 IPv6313
AS15474Rannsokna- og haskolanet Islands hf.UnclassifiedIPv4 IPv6157
AS2847Kauno Technologijos UniversitetasEducationIPv4 IPv6148
AS8501Institute of Bioorganic Chemistry Polish Academy of Science, Poznan Supercomputing and Networking CenterEducationIPv4 IPv6142
AS39590NORDUnetUnclassifiedIPv4 IPv683
AS198093Foreningen for digitala fri- och rattigheterUnclassifiedIPv4 IPv658
AS2832Vetenskapsradet / SUNETEducationIPv4 IPv636
AS3221Haridus- ja TeadusministeeriumEducationIPv4 IPv618
AS21320GEANT VerenigingUnclassifiedIPv415
AS6509CANARIE IncEducationIPv62

Adjacency

Adjacent networks

91 shown

Every AS seen directly next to AS2603 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS21320GEANT VerenigingUnclassifiedIPv4 IPv615,486
AS1653Vetenskapsradet / SUNETUnclassifiedIPv4 IPv66,710
AS34549meerfarbig GmbH & Co. KGHostingIPv4 IPv64,750
AS1299Arelion Sweden ABTransitIPv4 IPv63,506
AS8501Institute of Bioorganic Chemistry Polish Academy of Science, Poznan Supercomputing and Networking CenterEducationIPv4 IPv62,722
AS1741Tieteen tietotekniikan keskus OyUnclassifiedIPv4 IPv62,496
AS3741Dimension DataUnclassifiedIPv41,617
AS224Sikt - Kunnskapssektorens TjenesteleverandorUnclassifiedIPv4 IPv61,611
AS20514Axians ABHostingIPv41,456
AS37100SEACOM LimitedUnclassifiedIPv41,449
AS50304Blix Solutions ASUnclassifiedIPv4 IPv61,418
AS49788Nexthop ASUnclassifiedIPv41,407
AS48362Stadtwerke FeldkirchResidentialIPv4 IPv61,399
AS42708Glesys ABUnclassifiedIPv41,389
AS3333Reseaux IP Europeens Network Coordination Centre (RIPE NCC)UnclassifiedIPv4 IPv61,376
AS6696VERIXI SAUnclassifiedIPv41,344
AS6939Hurricane Electric LLCTransitIPv4 IPv61,289
AS56655Gigahost ASUnclassifiedIPv4 IPv61,199
AS24482SG.GSHostingIPv4 IPv6977
AS11537Internet2UnclassifiedIPv4 IPv6887
AS1835IDDQD-ASUnclassifiedIPv4 IPv6871
AS8674Netnod ABUnclassifiedIPv4 IPv6802
AS34019Hivane AssociationUnclassifiedIPv4 IPv6595
AS14907Wikimedia Foundation Inc.HostingIPv4 IPv6580
AS1836green.ch AGResidentialIPv4 IPv6556
AS852TELUS Communications Inc.ResidentialIPv4 IPv6507
AS293ESnetUnclassifiedIPv4468
AS2497Internet Initiative Japan Inc.UnclassifiedIPv4466
AS48185team.blue NVUnclassifiedIPv4430
AS6762TELECOM ITALIA SPARKLE S.p.A.TransitIPv4 IPv6427
AS9002RETN LimitedUnclassifiedIPv4 IPv6417
AS4635Hong Kong Internet Exchange--Route Server 1UnclassifiedIPv4 IPv6279
AS7575Australian Academic and Research Network (AARNet)EducationIPv4 IPv6272
AS2847Kauno Technologijos UniversitetasEducationIPv4 IPv6261
AS6461Zayo BandwidthTransitIPv4234
AS15474Rannsokna- og haskolanet Islands hf.UnclassifiedIPv4 IPv6218
AS33891Core-Backbone GmbHHostingIPv4 IPv6211
AS3491PCCW Global (HK) Ltd.TransitIPv4 IPv6182
AS20473The Constant Company, LLCHostingIPv6181
AS12389PJSC RostelecomResidentialIPv4175
AS1273IDDQD-ASBusinessIPv4 IPv6162
AS6830Liberty Global Europe Holding B.V.ResidentialIPv4149
AS12552GlobalConnect ABUnclassifiedIPv4121
AS3303Swisscom (Schweiz) AGResidentialIPv4 IPv6111
AS39590NORDUnetUnclassifiedIPv4 IPv683
AS2914NTT America, Inc.TransitIPv661
AS198093Foreningen for digitala fri- och rattigheterUnclassifiedIPv4 IPv658
AS3221Haridus- ja TeadusministeeriumEducationIPv4 IPv655
AS8434Telenor Sverige ABResidentialIPv439
AS2832Vetenskapsradet / SUNETEducationIPv4 IPv636
AS6509CANARIE IncEducationIPv633
AS20965GEANT VerenigingUnclassifiedIPv4 IPv615
AS29169GANDI SASHostingIPv412
AS12779IT.Gate S.p.A.UnclassifiedIPv44
AS31500Global Network Management IncUnclassifiedIPv43
AS1103SURF B.V.UnclassifiedIPv61

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

recorded

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.

ExchangeLocationTheir addressMember ports
DE-CIX FrankfurtFrankfurt, Germany80.81.192.2411,073
LINX LON1London, United Kingdom195.66.225.24925
AMS-IX AmsterdamAmsterdam, Netherlands80.249.209.203894
Neutral Internet ExchangeAmsterdam, Netherlands193.239.116.53665
Equinix Internet Exchange AshburnAshburn, United States206.126.236.230388
London Network Access PointLondon, United Kingdom5.57.80.168316
Hong Kong Internet ExchangeHong Kong, China123.255.91.213307
Equinix Internet Exchange ChicagoChicago, United States208.115.136.151280
Singapore Internet ExchangeSingapore, Singapore103.16.102.155273
JPIX TokyoTokyo, Japan210.171.225.238259
New York International Internet ExchangeNew York, United States198.32.160.21217
Internet Neutral Exchange Association CLG - LAN1Dublin, Ireland185.6.36.167115
Megaport Frankfurt IXFrankfurt, Germany62.69.146.103114
Sweden Open Network Internet eXchange StockholmStockholm, Sweden185.1.215.8097
STHIX - StockholmStockholm, Sweden192.121.80.4591
Stockholm Internet ExchangeStockholm, Sweden192.121.80.4591
Norwegian Internet Exchange Oslo 1Oslo, Norway185.1.55.570
Megaport Hamburg IXHamburg, Germany193.42.155.6762
CERN IXP / Equinix Internet Exchange GenevaGeneva, Switzerland192.65.185.13254
Reykjavik Internet ExchangeReykjavik, Iceland195.130.211.1230
Asteroid Amsterdam IXAmsterdam, Netherlands185.1.94.2027
Tampere Region ExchangeTampere, Finland195.140.192.1527
STHIX - CopenhagenCopenhagen, Denmark185.1.88.1821
Netnod Sundsvall- GävleSundsvall, Sweden194.68.128.2418

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.