asn.dev

Observed topology

AS39521 TNGNET

Unclassified RIPE

Upstreams 21 carry this network
Downstreams 7 this network carries
Adjacent (IPv4) 24
Adjacent (IPv6) 20
Upstream graph Who carries AS39521, and who carries them, drawn as a map up to the transit-free core. 3 exchanges Where AS39521 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

All 21

Networks observed carrying traffic for AS39521: 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
AS6939Hurricane Electric LLCTransitIPv4 IPv61,322
AS174Cogent Communications, LLCTransitIPv4 IPv6484
AS5511Orange S.A.TransitIPv4211
AS6830Liberty Global Europe Holding B.V.ResidentialIPv4197
AS61138Zappie Host LLCUnclassifiedIPv4 IPv695
AS50673Serverius Holding B.V.UnclassifiedIPv476
AS6206Netrouting B.V.HostingIPv459
AS50304Blix Solutions ASUnclassifiedIPv4 IPv644
AS24482SG.GSHostingIPv4 IPv641
AS20766Association "Gitoyen"UnclassifiedIPv438

All 21 upstreams →

Transit

Downstream networks

inferred

Networks for which AS39521 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS47690TNGNET B.V.UnclassifiedIPv42,656
AS213784TNGNET B.V.UnclassifiedIPv42,280
AS60117Host Sailor LtdUnclassifiedIPv4 IPv62,126
AS61060NXTcom Nederland BVUnclassifiedIPv4 IPv6625
AS207778Jacobus HuijbrechtsUnclassifiedIPv4 IPv6115
AS31800DALnetUnclassifiedIPv496
AS24381BGP.ExchangeHostingIPv633

Adjacency

Adjacent networks

All 30

Every AS seen directly next to AS39521 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS6939Hurricane Electric LLCTransitIPv4 IPv64,021
AS47690TNGNET B.V.UnclassifiedIPv42,656
AS213784TNGNET B.V.UnclassifiedIPv42,280
AS60117Host Sailor LtdUnclassifiedIPv4 IPv62,126
AS6206Netrouting B.V.HostingIPv42,065
AS174Cogent Communications, LLCTransitIPv4 IPv61,492
AS61138Zappie Host LLCUnclassifiedIPv4 IPv6685
AS61060NXTcom Nederland BVUnclassifiedIPv4 IPv6625
AS6830Liberty Global Europe Holding B.V.ResidentialIPv4593
AS5511Orange S.A.TransitIPv4 IPv6554

All 30 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-12 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.21M 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.