Observed topology

AS4004 Cogent Communications, LLC

Unclassified ARIN

Upstreams 0 carry this network

Downstreams 1 this network carries

Adjacent (IPv4) 23

Adjacent (IPv6) 15

Upstream graph Who carries AS4004, and who carries them, drawn as a map up to the transit-free core. 3 exchanges Where AS4004 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS4004: 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.

No upstream observed. Typical for a tier-1 network that buys transit from nobody.

Transit

Downstream networks

inferred

Networks for which AS4004 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS51964	ORANGE BUSINESS SERVICES U.S. Inc.	Unclassified	IPv4 IPv6	1,279

Adjacency

Adjacent networks

All 26

Every AS seen directly next to AS4004 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS51964	ORANGE BUSINESS SERVICES U.S. Inc.	Unclassified	IPv4 IPv6	1,283
AS5511	Orange S.A.	Transit	IPv4 IPv6	689
AS6939	Hurricane Electric LLC	Transit	IPv4 IPv6	205
AS34549	meerfarbig GmbH & Co. KG	Hosting	IPv4 IPv6	52
AS33891	Core-Backbone GmbH	Hosting	IPv4	31
AS6461	Zayo Bandwidth	Transit	IPv4	23
AS42708	Glesys AB	Unclassified	IPv4 IPv6	22
AS37721	Virtual Technologies & Solutions	Residential	IPv4 IPv6	21
AS48185	team.blue NV	Unclassified	IPv4 IPv6	20
AS50300	CustodianDC Limited	Unclassified	IPv4 IPv6	20

All 26 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-22 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.12M 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.