asn.dev

Observed topology

AS209531 OSTV SIX

Residential RIPE

Upstreams 9 carry this network
Downstreams 1 this network carries
Adjacent (IPv4) 10
Adjacent (IPv6) 7
Upstream graph Who carries AS209531, and who carries them, drawn as a map up to the transit-free core. 2 exchanges Where AS209531 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS209531: 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
AS39392SH.cz s.r.o.HostingIPv4 IPv6128
AS6939Hurricane Electric LLCTransitIPv4 IPv6102
AS31230Slovak University of Technology in BratislavaUnclassifiedIPv4 IPv614
AS3303Swisscom (Schweiz) AGResidentialIPv4 IPv612
AS24482SG.GSHostingIPv4 IPv66
AS29504Freenet Liberec, z.s.UnclassifiedIPv4 IPv66
AS37721Virtual Technologies & SolutionsResidentialIPv4 IPv66
AS20562Broadband Hosting B.V.HostingIPv42
AS33891Core-Backbone GmbHHostingIPv42

Transit

Downstream networks

inferred

Networks for which AS209531 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS208882Automation & Business, s.r.o.ResidentialIPv47

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS209531 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS39392SH.cz s.r.o.HostingIPv4 IPv6135
AS6939Hurricane Electric LLCTransitIPv4 IPv6102
AS31230Slovak University of Technology in BratislavaUnclassifiedIPv4 IPv614
AS3303Swisscom (Schweiz) AGResidentialIPv4 IPv612
AS208882Automation & Business, s.r.o.ResidentialIPv47
AS24482SG.GSHostingIPv4 IPv66
AS29504Freenet Liberec, z.s.UnclassifiedIPv4 IPv66
AS37721Virtual Technologies & SolutionsResidentialIPv4 IPv66
AS20562Broadband Hosting B.V.HostingIPv42
AS33891Core-Backbone GmbHHostingIPv42

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-23 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.15M 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.