Autonomous system profile

Review registration details, announced prefixes, network relationships and historical snapshots.

AS33666

Announcement observedARIN

CMCS - Comcast Cable Communications, LLC · CMCS

This profile is assembled from CHA.LA's normalized registration, routing and observation snapshots.

Last active10/2/2026, 16:02:58Snapshot expired

View network topology RDAP registration

ASN: AS33666
Registration country: United States
Name: CMCS - Comcast Cable Communications, LLC
Abbreviation: CMCS
Registration date: 2/16/2005, 19:59:31
Status: Announcement observed
RIR: ARIN

Network relationships and announced prefixes

ASN / prefix	Description / organization	Geographic scope	First seen	Last active	IPv4	IPv6	Status
199.120.255.0/24BGP · IPv4	Announced prefixBGP route observation	Not applicable · BGP prefix	9/18/2026, 08:00:00	10/13/2026, 08:00:00	✓	×	Currently valid
66.170.177.0/24BGP · IPv4	Announced prefixBGP route observation	Not applicable · BGP prefix	9/18/2026, 08:00:00	10/13/2026, 08:00:00	✓	×	Currently valid
66.170.179.0/24BGP · IPv4	Announced prefixBGP route observation	Not applicable · BGP prefix	9/18/2026, 08:00:00	10/13/2026, 08:00:00	✓	×	Currently valid

BGP prefixes have no geographic country; the column is marked not applicable.

Registration and sources

Organization: CMCS - Comcast Cable Communications, LLC
RIR: ARIN
Registration country: United States
Registration date: 2/16/2005, 19:59:31
Abuse contact: abuse@comcast.net

Snapshot trend

10/2/2026, 16:02:583 v43 v61 Upstream · 0 Uncertain

ASN route snapshotThis page reads collected ASN, prefix, relationship and history data. External interfaces are used for initial collection and scheduled refreshes.Source keys: cha-la-external-routing · rir-rdap-asn · iana-rdap-asn-bootstrap