asn.dev

Autonomous system

AS33652 CMCS

Unclassified ARIN

IPv4 addresses 1.76M 166 prefixes
IPv6 prefixes 150 counted as prefixes, not addresses
Countries 1 mostly US
Exchanges 0 recorded by PCH
Upstreams 2 71 downstream
Flagged prefixes 0 none

Summary

Comcast

United States of America · AI-generated

residential cable isp us

CMCS is the AS handle for Comcast Cable Communications, LLC.

What it's used for

  • The space carries residential cable internet and VoIP services, evidenced by netnames like DENVER-CPE-18, COMCAST-VOIP-4, and reverse DNS entries such as c-75-70-128-0.hsd1.co.comcast.net.
  • With 1,759,744 IPv4 addresses announced across 166 prefixes and 78 observed neighbours, the high address-to-neighbour ratio indicates a large-scale access network rather than a transit provider.

Notable

  • Registrants consistently identify as Comcast Cable Communications entities, including Comcast Cable Communications, LLC and Comcast Cable Communications Holdings, Inc, aligning with the announcer.
  • The address inventory is heavily concentrated in the Denver and Colorado regions, as reflected in netnames like COLORADO-10 and DENVER-5, suggesting this AS covers a specific regional footprint within Comcast's broader national infrastructure.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.

Interconnection

Peering at a glance

Full topology · Graph

Internet exchanges

No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.

Transit providers

2 upstream, 71 downstream and 80 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS7922Comcast Cable Communications, LLC6,515
AS3356Level 3 Parent, LLC124

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-11, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.

Address space

Summary

Shape and geography

IPv4 166 prefixes · 1.76M addresses IPv6 150 prefixes

CountryNamePrefixes
USUnited States of America316

Registry

Allocation record

ARIN · via Atlas (registry + RDAP)
Registry
ARIN
Handle
AS33652
Registry name
CMCS
Registrant
Comcast Cable Communications, LLC
Abuse contact
abuse@comcast.net
Registered
2005-02-16
Last changed
2021-01-25
Allocation
assigned

Routing security

RPKI and IRR

Full detail
RPKI
97% valid · 177 valid, 5 with no ROA
ROAs
497 authorising AS33652
ASPA
no ASPA record
IRR
83% registered · 151 of 182 announcements 2 other origin
Route objects
288 naming AS33652

Reputation

Classification and threat

Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.

Spamhaus DROP

Not on ASN-DROP The network as a whole is not listed.

No DROP prefixes None of its announced space is on the DROP prefix list.

Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 431 networks and 1,768 prefixes, as published 2026-10-12. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.

FBI IC3

No IC3 indicators Nothing from the FBI IC3 feed.

IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.

Elsewhere

Cross-check