Observed topology

AS21371 EQUINIX-UK-ASN

Unclassified RIPE

Upstreams 1 carry this network

Downstreams 6 this network carries

Adjacent (IPv4) 7

Adjacent (IPv6) 0

Upstream graph Who carries AS21371, and who carries them, drawn as a map up to the transit-free core. 1 exchange Where AS21371 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS21371: 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
AS15830	Equinix (EMEA) Acquisition Enterprises B.V.	Hosting	IPv4	120

Transit

Downstream networks

inferred

Networks for which AS21371 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS39633	COMPUTER SYSTEMS INTEGRATION GROUP LIMITED	Unclassified	IPv4	236
AS44980	Paul Cairney	Unclassified	IPv4	118
AS1766	Exxon Mobil Corporation	Unclassified	IPv4	59
AS62586	Trace One Inc.	Unclassified	IPv4	45
AS40992	Marex Financial Ltd	Unclassified	IPv4	34
AS210211	Sumup Limited	Unclassified	IPv4	32

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS21371 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS15830	Equinix (EMEA) Acquisition Enterprises B.V.	Hosting	IPv4	644
AS39633	COMPUTER SYSTEMS INTEGRATION GROUP LIMITED	Unclassified	IPv4	236
AS44980	Paul Cairney	Unclassified	IPv4	118
AS1766	Exxon Mobil Corporation	Unclassified	IPv4	59
AS62586	Trace One Inc.	Unclassified	IPv4	45
AS40992	Marex Financial Ltd	Unclassified	IPv4	34
AS210211	Sumup Limited	Unclassified	IPv4	32

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-15 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.09M 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.