asn.dev

Observed topology

AS39521 TNGNET

Unclassified RIPE

Upstreams 27 carry this network
Downstreams 7 this network carries
Adjacent (IPv4) 31
Adjacent (IPv6) 21
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 27

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 IPv61,268
AS174Cogent Communications, LLCTransitIPv4 IPv6524
AS6830Liberty Global Europe Holding B.V.ResidentialIPv4 IPv6288
AS5511Orange S.A.TransitIPv4221
AS61138Zappie Host LLCUnclassifiedIPv4 IPv696
AS50673Serverius Holding B.V.UnclassifiedIPv488
AS50304Blix Solutions ASUnclassifiedIPv4 IPv686
AS6206Netrouting B.V.HostingIPv460
AS24482SG.GSHostingIPv4 IPv659
AS37721Virtual Technologies & SolutionsResidentialIPv456

All 27 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
AS213784TNGNET B.V.UnclassifiedIPv42,809
AS47690TNGNET B.V.UnclassifiedIPv42,617
AS60117Host Sailor LtdUnclassifiedIPv4 IPv62,340
AS61060NXTcom Nederland BVUnclassifiedIPv4 IPv6633
AS207778Jacobus HuijbrechtsUnclassifiedIPv4 IPv6117
AS31800DALnetUnclassifiedIPv498
AS24381BGP.ExchangeHostingIPv633

Adjacency

Adjacent networks

All 36

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

ASNetworkTypeFamiliesPaths seen
AS6939Hurricane Electric LLCTransitIPv4 IPv64,137
AS213784TNGNET B.V.UnclassifiedIPv42,809
AS47690TNGNET B.V.UnclassifiedIPv42,617
AS60117Host Sailor LtdUnclassifiedIPv4 IPv62,340
AS6206Netrouting B.V.HostingIPv41,868
AS174Cogent Communications, LLCTransitIPv4 IPv61,646
AS6830Liberty Global Europe Holding B.V.ResidentialIPv4 IPv6875
AS5511Orange S.A.TransitIPv4 IPv6670
AS61138Zappie Host LLCUnclassifiedIPv4 IPv6640
AS61060NXTcom Nederland BVUnclassifiedIPv4 IPv6633

All 36 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-31 10:00 UTC by route-views2,rrc00, as seen from 76 BGP vantage points across 74.50M 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.