Observed topology

AS39551 GENCAT-AS Centre de Telecomunicacions i Tecnologies de la Informacio de la Generalitat de Catalunya

Unclassified RIPE

Upstreams 2 carry this network

Downstreams 3 this network carries

Adjacent (IPv4) 5

Adjacent (IPv6) 0

Upstream graph Who carries AS39551, and who carries them, drawn as a map up to the transit-free core. 2 exchanges Where AS39551 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS39551: 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.

AS	Network	Type	Families	Paths seen
AS12479	Orange Espagne SA	Residential	IPv4	4,380
AS3352	TELEFONICA DE ESPANA S.A.U.	Mobile	IPv4	180

Transit

Downstream networks

inferred

Networks for which AS39551 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS21193	Centre de Telecomunicacions i Tecnologies de la Informacio de la Generalitat de Catalunya	Unclassified	IPv4	1,380
AS16153	Servei Catala de la Salut	Unclassified	IPv4	180
AS25412	CORPORACIO CATALANA DE MITJANS AUDIOVISUALS, S.A.	Unclassified	IPv4	2

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS39551 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS12479	Orange Espagne SA	Residential	IPv4	5,520
AS21193	Centre de Telecomunicacions i Tecnologies de la Informacio de la Generalitat de Catalunya	Unclassified	IPv4	1,380
AS3352	TELEFONICA DE ESPANA S.A.U.	Mobile	IPv4	602
AS16153	Servei Catala de la Salut	Unclassified	IPv4	180
AS25412	CORPORACIO CATALANA DE MITJANS AUDIOVISUALS, S.A.	Unclassified	IPv4	2

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-01 10:00 UTC by route-views2,rrc00, as seen from 76 BGP vantage points across 74.48M 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.