Observed topology

AS21057 OVERON-SPAIN-AS Ciudad de la Imagen - Madrid

Unclassified RIPE

Upstreams 9 carry this network

Downstreams 0 this network carries

Adjacent (IPv4) 9

Adjacent (IPv6) 0

Upstream graph Who carries AS21057, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS21057 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS21057: 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
AS3356	Level 3 Parent, LLC	Transit	IPv4	642
AS174	Cogent Communications, LLC	Transit	IPv4	97
AS19332	COORDINADORA DE CARRIER'S, S.A. DE C.V.	Unclassified	IPv4	92
AS32098	Transtelco Inc	Unclassified	IPv4	86
AS6762	TELECOM ITALIA SPARKLE S.p.A.	Transit	IPv4	78
AS7018	AT&T Enterprises, LLC	Residential	IPv4	63
AS3257	GTT Communications Inc.	Transit	IPv4	58
AS8866	Vivacom Bulgaria EAD	Residential	IPv4	33
AS41313	"NOVATEL" EOOD	Unclassified	IPv4	28

Transit

Downstream networks

inferred

Networks for which AS21057 was observed as the last hop before the origin, meaning it appears to provide them transit.

No downstream observed. This network does not appear to carry transit for anyone.

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS21057 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS3356	Level 3 Parent, LLC	Transit	IPv4	642
AS174	Cogent Communications, LLC	Transit	IPv4	97
AS19332	COORDINADORA DE CARRIER'S, S.A. DE C.V.	Unclassified	IPv4	92
AS32098	Transtelco Inc	Unclassified	IPv4	86
AS6762	TELECOM ITALIA SPARKLE S.p.A.	Transit	IPv4	78
AS7018	AT&T Enterprises, LLC	Residential	IPv4	63
AS3257	GTT Communications Inc.	Transit	IPv4	58
AS8866	Vivacom Bulgaria EAD	Residential	IPv4	33
AS41313	"NOVATEL" EOOD	Unclassified	IPv4	28

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-20 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.16M 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.