Observed topology
AS2852 CESNET2
Transit
Upstream networks
Networks observed carrying traffic for AS2852: 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 |
|---|---|---|---|---|
| AS60606 | PRO-ZETA a.s. | Unclassified | IPv4 IPv6 | 704 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 240 |
| AS20965 | GEANT Vereniging | Unclassified | IPv4 IPv6 | 131 |
| AS1853 | ACONET | Unclassified | IPv4 | 104 |
| AS34549 | meerfarbig GmbH & Co. KG | Hosting | IPv4 | 78 |
| AS50673 | Serverius Holding B.V. | Unclassified | IPv4 | 52 |
| AS50300 | CustodianDC Limited | Unclassified | IPv4 IPv6 | 27 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 27 |
| AS29504 | Freenet Liberec, z.s. | Unclassified | IPv4 IPv6 | 27 |
| AS3333 | Reseaux IP Europeens Network Coordination Centre (RIPE NCC) | Unclassified | IPv4 IPv6 | 27 |
| AS48362 | Stadtwerke Feldkirch | Residential | IPv4 IPv6 | 27 |
| AS34927 | iFog GmbH | Hosting | IPv4 | 26 |
| AS6461 | Zayo Bandwidth | Transit | IPv4 | 26 |
| AS48185 | team.blue NV | Unclassified | IPv4 | 26 |
| AS20485 | Joint Stock Company TransTeleCom | Unclassified | IPv4 | 26 |
| AS57463 | NetIX Communications JSC | Unclassified | IPv4 | 26 |
| AS37100 | SEACOM Limited | Unclassified | IPv4 | 26 |
| AS12552 | GlobalConnect AB | Unclassified | IPv4 | 26 |
| AS37721 | Virtual Technologies & Solutions | Residential | IPv4 | 26 |
| AS20766 | Association "Gitoyen" | Unclassified | IPv4 | 26 |
| AS2607 | Zdruzenie pouzivatelov Slovenskej akademickej datovej siete SANET | Education | IPv4 | 25 |
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 AS2852 was observed as the last hop before the origin, meaning it appears to provide them transit.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS208093 | Moravskoslezsky kraj | Unclassified | IPv4 | 285 |
| AS197451 | Brno University of Technology | Education | IPv4 IPv6 | 267 |
| AS48091 | Kraj Vysocina | Unclassified | IPv4 IPv6 | 262 |
| AS197277 | State Institute for Drug Control | Unclassified | IPv4 IPv6 | 230 |
| AS199711 | National Cyber and Information Security Agency | Unclassified | IPv4 IPv6 | 197 |
| AS201648 | Plzensky kraj | Unclassified | IPv4 IPv6 | 166 |
| AS213152 | Narodni bezpecnostni urad Czech Republic | Unclassified | IPv4 IPv6 | 115 |
| AS61110 | Sprava informacnich technologii mesta Plzne, p.o. | Unclassified | IPv4 IPv6 | 110 |
| AS2607 | Zdruzenie pouzivatelov Slovenskej akademickej datovej siete SANET | Education | IPv4 IPv6 | 105 |
| AS200874 | Liberecky kraj | Unclassified | IPv4 IPv6 | 103 |
| AS212876 | Pardubicky Kraj | Unclassified | IPv4 IPv6 | 103 |
| AS210498 | Kraj Vysocina | Unclassified | IPv4 IPv6 | 102 |
| AS202874 | Zlinsky Kraj | Unclassified | IPv4 IPv6 | 102 |
| AS210367 | Krajska zdravotni, a.s. | Unclassified | IPv4 IPv6 | 92 |
| AS51727 | Doosan Skoda Power s.r.o | Unclassified | IPv4 | 59 |
| AS204772 | Reditelstvi silnic a dalnic s.p. | Unclassified | IPv4 IPv6 | 45 |
| AS1853 | ACONET | Unclassified | IPv4 IPv6 | 35 |
| AS198500 | Ustav vypocetni techniky | Unclassified | IPv4 IPv6 | 33 |
| AS199604 | OLOMOUCKY KRAJ | Unclassified | IPv4 | 16 |
Adjacency
Adjacent networks
Every AS seen directly next to AS2852 in a routing path, in either direction.
| AS | Network | Type | Families | Paths seen |
|---|---|---|---|---|
| AS60606 | PRO-ZETA a.s. | Unclassified | IPv4 IPv6 | 1,388 |
| AS6939 | Hurricane Electric LLC | Transit | IPv4 IPv6 | 1,014 |
| AS1853 | ACONET | Unclassified | IPv4 IPv6 | 407 |
| AS20965 | GEANT Vereniging | Unclassified | IPv4 IPv6 | 318 |
| AS208093 | Moravskoslezsky kraj | Unclassified | IPv4 | 285 |
| AS197451 | Brno University of Technology | Education | IPv4 IPv6 | 267 |
| AS48091 | Kraj Vysocina | Unclassified | IPv4 IPv6 | 262 |
| AS197277 | State Institute for Drug Control | Unclassified | IPv4 IPv6 | 230 |
| AS199711 | National Cyber and Information Security Agency | Unclassified | IPv4 IPv6 | 197 |
| AS29504 | Freenet Liberec, z.s. | Unclassified | IPv4 IPv6 | 194 |
| AS24482 | SG.GS | Hosting | IPv4 IPv6 | 180 |
| AS34549 | meerfarbig GmbH & Co. KG | Hosting | IPv4 IPv6 | 171 |
| AS201648 | Plzensky kraj | Unclassified | IPv4 IPv6 | 166 |
| AS2607 | Zdruzenie pouzivatelov Slovenskej akademickej datovej siete SANET | Education | IPv4 IPv6 | 154 |
| AS213152 | Narodni bezpecnostni urad Czech Republic | Unclassified | IPv4 IPv6 | 115 |
| AS61110 | Sprava informacnich technologii mesta Plzne, p.o. | Unclassified | IPv4 IPv6 | 110 |
| AS200874 | Liberecky kraj | Unclassified | IPv4 IPv6 | 103 |
| AS212876 | Pardubicky Kraj | Unclassified | IPv4 IPv6 | 103 |
| AS210498 | Kraj Vysocina | Unclassified | IPv4 IPv6 | 102 |
| AS202874 | Zlinsky Kraj | Unclassified | IPv4 IPv6 | 102 |
| AS210367 | Krajska zdravotni, a.s. | Unclassified | IPv4 IPv6 | 92 |
| AS57463 | NetIX Communications JSC | Unclassified | IPv4 | 89 |
| AS21320 | GEANT Vereniging | Unclassified | IPv4 | 64 |
| AS51727 | Doosan Skoda Power s.r.o | Unclassified | IPv4 | 59 |
| AS37721 | Virtual Technologies & Solutions | Residential | IPv4 IPv6 | 59 |
| AS37100 | SEACOM Limited | Unclassified | IPv4 | 55 |
| AS12552 | GlobalConnect AB | Unclassified | IPv4 | 53 |
| AS50673 | Serverius Holding B.V. | Unclassified | IPv4 | 52 |
| AS20485 | Joint Stock Company TransTeleCom | Unclassified | IPv4 | 52 |
| AS6461 | Zayo Bandwidth | Transit | IPv4 | 46 |
| AS204772 | Reditelstvi silnic a dalnic s.p. | Unclassified | IPv4 IPv6 | 45 |
| AS48362 | Stadtwerke Feldkirch | Residential | IPv4 IPv6 | 34 |
| AS198500 | Ustav vypocetni techniky | Unclassified | IPv4 IPv6 | 33 |
| AS3333 | Reseaux IP Europeens Network Coordination Centre (RIPE NCC) | Unclassified | IPv4 IPv6 | 27 |
| AS50300 | CustodianDC Limited | Unclassified | IPv4 IPv6 | 27 |
| AS34927 | iFog GmbH | Hosting | IPv4 | 26 |
| AS8218 | Zayo Infrastructure France SA | Unclassified | IPv4 | 26 |
| AS48185 | team.blue NV | Unclassified | IPv4 | 26 |
| AS20766 | Association "Gitoyen" | Unclassified | IPv4 | 26 |
| AS20723 | AVONET, s.r.o. | Residential | IPv4 | 20 |
| AS199604 | OLOMOUCKY KRAJ | Unclassified | IPv4 | 16 |
| AS1836 | green.ch AG | Residential | IPv4 IPv6 | 7 |
| AS29632 | Netassist International EOOD | Unclassified | IPv6 | 6 |
| AS16019 | Vodafone Czech Republic a.s. | Unclassified | IPv6 | 5 |
| AS12779 | IT.Gate S.p.A. | Unclassified | IPv4 | 5 |
| AS56662 | Marcin Gondek | Unclassified | IPv6 | 5 |
| AS213241 | TECHIT.BE SRL | Residential | IPv6 | 4 |
| AS33891 | Core-Backbone GmbH | Hosting | IPv4 | 2 |
| AS202297 | Skylon Solutions Limited | Unclassified | IPv4 | 2 |
| AS12859 | BIT BV | Hosting | IPv6 | 1 |
| AS34019 | Hivane Association | Unclassified | IPv6 | 1 |
| AS212024 | Marc Schmitt | Unclassified | IPv6 | 1 |
| AS17639 | Converge ICT Solutions Inc. | 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 AS2852, 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 2 exchanges across 2 countries and 1 region.
| Exchange | Location | Their address | Member ports |
|---|---|---|---|
| DE-CIX Frankfurt | Frankfurt, Germany | 80.81.194.214 | 1,073 |
| AMS-IX Amsterdam | Amsterdam, Netherlands | 80.249.209.106 | 894 |
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.