asn.dev

Observed topology

AS25248 BLUETONE-AS The Czech Republic

Upstreams 8 carry this network
Downstreams 26 this network carries
Adjacent (IPv4) 33
Adjacent (IPv6) 20

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS25248: 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 IPv6170
AS6939Hurricane Electric LLCTransitIPv4 IPv6105
AS174Cogent Communications, LLCTransitIPv4 IPv669
AS24482SG.GSHostingIPv4 IPv67
AS29504Freenet Liberec, z.s.UnclassifiedIPv4 IPv67
AS57463NetIX Communications JSCUnclassifiedIPv45
AS37721Virtual Technologies & SolutionsResidentialIPv45
AS31230Slovak University of Technology in BratislavaUnclassifiedIPv45

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 AS25248 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS206438MX-NET Telekomunikace s.r.o.UnclassifiedIPv4 IPv6538
AS47110Cloud4com s.r.o.HostingIPv4 IPv6324
AS206712FELDSAM s.r.o.UnclassifiedIPv4 IPv6291
AS204351NAM system, a.s.UnclassifiedIPv4126
AS213223GasNet, s.r.o.UnclassifiedIPv4112
AS215704NGN CZ s.r.o.UnclassifiedIPv4 IPv6107
AS59925Seonet Multimedia s.r.o.UnclassifiedIPv4 IPv697
AS199600Virtis s.r.o.UnclassifiedIPv4 IPv697
AS213359Jan KorinekUnclassifiedIPv4 IPv696
AS39790Web4U s.r.o.HostingIPv492
AS25192CZ.NIC, z.s.p.o.UnclassifiedIPv4 IPv687
AS57496Praha1.net z.s.p.o.UnclassifiedIPv4 IPv687
AS52058za200.cz s.r.o.UnclassifiedIPv483
AS201594Czech Telecommunication OfficeUnclassifiedIPv4 IPv680
AS51331SychrovNET s.r.oHostingIPv4 IPv674
AS207391E LINKX a.s.UnclassifiedIPv460
AS202073Itego a.s.UnclassifiedIPv460
AS202556Blond & Brown s.r.o.UnclassifiedIPv460
AS57904Vevynet s.r.o.UnclassifiedIPv460
AS205724T.S.BOHEMIA a.s.UnclassifiedIPv457
AS48405CGI IT Czech Republic s.r.o.UnclassifiedIPv456
AS196822SELECT SYSTEM, s.r.o.UnclassifiedIPv4 IPv641
AS206613Tipsport.net a.s.UnclassifiedIPv4 IPv629
AS196762ALKOM Security, a.s.UnclassifiedIPv48
AS43070JAW.cz s.r.o.ResidentialIPv63
AS11521ModusLink CorporationUnclassifiedIPv43

Adjacency

Adjacent networks

53 shown

Every AS seen directly next to AS25248 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS1299Arelion Sweden ABTransitIPv4 IPv61,221
AS6939Hurricane Electric LLCTransitIPv4 IPv61,139
AS174Cogent Communications, LLCTransitIPv4 IPv6693
AS206438MX-NET Telekomunikace s.r.o.UnclassifiedIPv4 IPv6538
AS47110Cloud4com s.r.o.HostingIPv4 IPv6327
AS206712FELDSAM s.r.o.UnclassifiedIPv4 IPv6291
AS25192CZ.NIC, z.s.p.o.UnclassifiedIPv4 IPv6237
AS204351NAM system, a.s.UnclassifiedIPv4126
AS213223GasNet, s.r.o.UnclassifiedIPv4112
AS215704NGN CZ s.r.o.UnclassifiedIPv4 IPv6107
AS51331SychrovNET s.r.oHostingIPv4 IPv698
AS59925Seonet Multimedia s.r.o.UnclassifiedIPv4 IPv697
AS199600Virtis s.r.o.UnclassifiedIPv4 IPv697
AS213359Jan KorinekUnclassifiedIPv4 IPv696
AS39790Web4U s.r.o.HostingIPv492
AS57496Praha1.net z.s.p.o.UnclassifiedIPv4 IPv687
AS52058za200.cz s.r.o.UnclassifiedIPv483
AS201594Czech Telecommunication OfficeUnclassifiedIPv4 IPv680
AS207391E LINKX a.s.UnclassifiedIPv460
AS202073Itego a.s.UnclassifiedIPv460
AS202556Blond & Brown s.r.o.UnclassifiedIPv460
AS57904Vevynet s.r.o.UnclassifiedIPv460
AS205724T.S.BOHEMIA a.s.UnclassifiedIPv457
AS48405CGI IT Czech Republic s.r.o.UnclassifiedIPv456
AS29504Freenet Liberec, z.s.UnclassifiedIPv4 IPv654
AS37721Virtual Technologies & SolutionsResidentialIPv447
AS31230Slovak University of Technology in BratislavaUnclassifiedIPv4 IPv647
AS24482SG.GSHostingIPv4 IPv645
AS196822SELECT SYSTEM, s.r.o.UnclassifiedIPv4 IPv641
AS57463NetIX Communications JSCUnclassifiedIPv432
AS206613Tipsport.net a.s.UnclassifiedIPv4 IPv629
AS196762ALKOM Security, a.s.UnclassifiedIPv48
AS43070JAW.cz s.r.o.ResidentialIPv63
AS11521ModusLink CorporationUnclassifiedIPv43

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 AS25248, 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.

ExchangeLocationTheir addressMember ports
Peering.czPrague, Czech Republic185.0.20.132212
Slovak Internet eXchange BratislavaBratislava, Slovakia192.108.148.6571

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.