Observed topology

AS33660 CMCS - Comcast Cable Communications, LLC

Unclassified ARIN Cable/DSL/ISP

Upstreams 2 carry this network

Downstreams 61 this network carries

Adjacent (IPv4) 63

Adjacent (IPv6) 6

Upstream graph Who carries AS33660, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS33660 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS33660: 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
AS7922	Comcast Cable Communications, LLC	Residential	IPv4 IPv6	2,013
AS3356	Level 3 Parent, LLC	Transit	IPv4	19

Transit

Downstream networks

All 61

Networks for which AS33660 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS19477	F J Management Inc.	Unclassified	IPv4	414
AS27178	Practice Management Technologies and Services	Unclassified	IPv4	98
AS54113	Fastly, Inc.	Hosting	IPv4 IPv6	94
AS23389	Campbell Scientific, Inc.	Unclassified	IPv4	76
AS11052	Intermountain Health Care, Inc.	Unclassified	IPv4	72
AS33741	Dennis Group	Unclassified	IPv4	67
AS54629	Associated Food Stores, Inc.	Unclassified	IPv4	65
AS393917	Cache Valley Electric Company	Unclassified	IPv4	65
AS400988	Salt Lake County	Unclassified	IPv4	61
AS10786	Chartway Federal Credit Union	Unclassified	IPv4	60

All 61 downstreams →

Adjacency

Adjacent networks

All 63

Every AS seen directly next to AS33660 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS7922	Comcast Cable Communications, LLC	Residential	IPv4 IPv6	3,877
AS3356	Level 3 Parent, LLC	Transit	IPv4 IPv6	526
AS19477	F J Management Inc.	Unclassified	IPv4	414
AS27178	Practice Management Technologies and Services	Unclassified	IPv4	98
AS54113	Fastly, Inc.	Hosting	IPv4 IPv6	94
AS23389	Campbell Scientific, Inc.	Unclassified	IPv4	76
AS11052	Intermountain Health Care, Inc.	Unclassified	IPv4	72
AS33741	Dennis Group	Unclassified	IPv4	67
AS54629	Associated Food Stores, Inc.	Unclassified	IPv4	65
AS393917	Cache Valley Electric Company	Unclassified	IPv4	65

All 63 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-04 10:00 UTC by route-views2,rrc00, as seen from 76 BGP vantage points across 74.33M 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.