asn.dev

Observed topology

AS39904 MERIT-AS MERIT GROUP a.s

Unclassified RIPE Cable/DSL/ISP

Upstreams 7 carry this network
Downstreams 4 this network carries
Adjacent (IPv4) 11
Adjacent (IPv6) 6
Upstream graph Who carries AS39904, and who carries them, drawn as a map up to the transit-free core. 1 exchange Where AS39904 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS39904: 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
AS6855Slovak Telekom, a.s.MobileIPv4102
AS6939Hurricane Electric LLCTransitIPv4 IPv665
AS16019Vodafone Czech Republic a.s.UnclassifiedIPv436
AS24482SG.GSHostingIPv4 IPv64
AS29504Freenet Liberec, z.s.UnclassifiedIPv4 IPv64
AS1764Next Layer Telekommunikationsdienstleistungs- und Beratungs GmbHUnclassifiedIPv43
AS8218Zayo Infrastructure France SAUnclassifiedIPv43

Transit

Downstream networks

inferred

Networks for which AS39904 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS199604OLOMOUCKY KRAJUnclassifiedIPv4 IPv677
AS47767Regionalni centrum Olomouc s.r.o.UnclassifiedIPv4 IPv648
AS205968GeneralNet s.r.o.UnclassifiedIPv4 IPv629
AS205724T.S.BOHEMIA a.s.UnclassifiedIPv46

Adjacency

Adjacent networks

All 11

Every AS seen directly next to AS39904 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS6939Hurricane Electric LLCTransitIPv4 IPv6164
AS6855Slovak Telekom, a.s.MobileIPv4134
AS199604OLOMOUCKY KRAJUnclassifiedIPv4 IPv677
AS16019Vodafone Czech Republic a.s.UnclassifiedIPv452
AS47767Regionalni centrum Olomouc s.r.o.UnclassifiedIPv4 IPv648
AS205968GeneralNet s.r.o.UnclassifiedIPv4 IPv629
AS29504Freenet Liberec, z.s.UnclassifiedIPv4 IPv610
AS24482SG.GSHostingIPv4 IPv68
AS205724T.S.BOHEMIA a.s.UnclassifiedIPv46
AS8218Zayo Infrastructure France SAUnclassifiedIPv45

All 11 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-14 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.46M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.

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. 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.

Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.