Observed topology

AS12 NYU-DOMAIN

Unclassified ARIN

Upstreams 8 carry this network

Downstreams 1 this network carries

Adjacent (IPv4) 9

Adjacent (IPv6) 4

Upstream graph Who carries AS12, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS12 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS12: 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
AS6461	Zayo Bandwidth	Transit	IPv4	280
AS3257	GTT Communications Inc.	Transit	IPv4 IPv6	215
AS3754	NYSERNet	Education	IPv4	70
AS3356	Level 3 Parent, LLC	Transit	IPv4 IPv6	64
AS3269	Telecom Italia S.p.A.	Residential	IPv4	51
AS46887	Crown Castle Fiber LLC	Unclassified	IPv4 IPv6	21
AS8220	COLT Technology Services Group Limited	Hosting	IPv4	20
AS137	Consortium GARR	Unclassified	IPv4	11

Transit

Downstream networks

inferred

Networks for which AS12 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS394666	NYU Langone Health	Unclassified	IPv4 IPv6	397

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS12 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS6461	Zayo Bandwidth	Transit	IPv4	398
AS394666	NYU Langone Health	Unclassified	IPv4 IPv6	397
AS3257	GTT Communications Inc.	Transit	IPv4 IPv6	360
AS3356	Level 3 Parent, LLC	Transit	IPv4 IPv6	114
AS3754	NYSERNet	Education	IPv4	98
AS46887	Crown Castle Fiber LLC	Unclassified	IPv4 IPv6	77
AS3269	Telecom Italia S.p.A.	Residential	IPv4	51
AS8220	COLT Technology Services Group Limited	Hosting	IPv4	20
AS137	Consortium GARR	Unclassified	IPv4	11

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.