AS33667 — CMCS - Comcast Cable Communications, LLC

AS33667 announces 183 IPv4 prefixes covering 999,936 addresses and 66 IPv6 prefixes.

About this network

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

What it's used for

• The address space carries residential cable internet services, evidenced by reverse DNS entries like c-67-181-127-255.hsd1.ca.comcast.net and netnames such as CENTRALCALI-CPE-17 and SACRAMENTO-9.
• With 996,352 IPv4 addresses announced across 181 prefixes and 137 observed neighbours, the high address-to-neighbour ratio indicates a large-scale access network rather than a transit provider.

Notable

• All sampled registrants align with the announcer, consistently listing Comcast Cable Communications, LLC or Comcast Cable Communications.
• The inventory is finely subdivided into regional blocks, including specific Central California and Sacramento designations, reflecting site-by-site segmentation of the corporate estate.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 5.182.186.0/24
• 5.182.193.0/24
• 5.182.194.0/23
• 9.142.48.0/20
• 9.142.96.0/19
• 16.5.8.0/23
• 23.30.32.0/20
• 23.230.200.0/21
• 24.2.32.0/19
• 24.7.128.0/18
• 24.10.0.0/17
• 36.255.215.0/24
• 40.27.174.0/23
• 45.67.141.0/24
• 50.73.48.0/20
• 50.79.152.0/21
• 50.189.0.0/19
• 50.191.32.0/19
• 50.192.216.0/21
• 50.194.16.0/20
• 50.203.5.0/24
• 50.203.201.0/24
• 50.207.246.0/24
• 50.209.64.0/19
• 50.211.96.0/19
• 50.213.96.0/19
• 50.222.62.0/24
• 50.236.209.0/24
• 50.239.185.0/24
• 50.245.160.0/19
• 50.250.160.0/19
• 50.255.224.0/19
• 63.246.148.0/24
• 63.246.152.0/24
• 63.246.159.0/24
• 66.208.208.0/22
• 66.208.212.0/23
• 66.208.227.0/24
• 66.208.235.0/24
• 66.208.248.0/23
• 67.161.160.0/19
• 67.164.208.0/20
• 67.164.228.0/22
• 67.166.128.0/19
• 67.169.224.0/20
• 67.172.112.0/20
• 67.172.160.0/19
• 67.174.32.0/19
• 67.174.144.0/20
• 67.181.0.0/16
• 67.182.0.0/17
• 67.182.160.0/19
• 67.187.128.0/17
• 68.85.27.0/24
• 68.85.104.0/23
• 68.85.120.0/24
• 68.85.196.0/24
• 68.87.200.0/22
• 68.87.212.0/23
• 68.87.221.0/24
• 69.139.197.0/24
• 69.241.21.0/24
• 69.252.74.0/23
• 69.252.224.0/23
• 70.88.54.0/23
• 70.89.8.0/22
• 70.89.144.0/22
• 70.90.52.0/23
• 70.90.214.0/23
• 70.91.118.0/24
• 70.91.190.0/23
• 71.19.136.0/22
• 71.27.96.0/19
• 71.193.0.0/18
• 71.195.96.0/19
• 71.195.160.0/19
• 71.197.64.0/18
• 74.1.24.0/23
• 74.92.246.0/24
• 74.92.248.0/24
• 74.93.20.0/22
• 74.93.162.0/23
• 74.93.176.0/21
• 74.95.106.0/24
• 74.95.108.0/23
• 75.144.96.0/22
• 75.144.228.0/22
• 75.146.84.0/23
• 75.146.138.0/23
• 75.147.230.0/23
• 75.147.232.0/21
• 75.150.2.0/23
• 75.151.70.0/23
• 76.20.0.0/17
• 76.29.160.0/20
• 76.105.0.0/18
• 76.114.0.0/18
• 76.125.32.0/19
• 76.127.64.0/18
• 76.137.128.0/17

and 149 more.

Upstream networks

• AS7922 Comcast Cable Communications, LLC
• AS3356 Level 3 Parent, LLC

Downstream networks

• AS23338 ASN-DCS-01
• AS2894 California Department of Water Resources
• AS11620 Succeed.Net
• AS32688 THE GOLDEN 1 CREDIT UNION
• AS11829 Cadence Design Systems, Inc.
• AS46341 California Public Utilities Commission
• AS25753 California Public Employees' Retirement System
• AS20940 Akamai International B.V.
• AS46867 Sebastian
• AS53782 Pacific Coast Producers
• AS397062 Sun-Maid Growers of California
• AS17381 Williams-Sonoma
• AS14443 Broadridge Financial Solutions, Inc.
• AS27580 CONVERGEONE HOLDINGS, INC.
• AS36040 Google LLC
• AS22768 SYNERGY BROADBAND
• AS18841 Trimble, Inc.
• AS397909 Elk Grove Unified School District
• AS13395 SMART CITY NETWORKS, LIMITED PARTNERSHIP
• AS11681 Integrity Networks
• AS54113 Fastly, Inc.
• AS13335 Cloudflare, Inc.
• AS10309 County of Marin
• AS27009 Clovis Unified School District
• AS394377 County of Tulare

Adjacent networks

• AS7922 Comcast Cable Communications, LLC
• AS3356 Level 3 Parent, LLC
• AS23338 ASN-DCS-01
• AS2894 California Department of Water Resources
• AS11620 Succeed.Net
• AS32688 THE GOLDEN 1 CREDIT UNION
• AS11829 Cadence Design Systems, Inc.
• AS46341 California Public Utilities Commission
• AS25753 California Public Employees' Retirement System
• AS20940 Akamai International B.V.
• AS46867 Sebastian
• AS53782 Pacific Coast Producers
• AS397062 Sun-Maid Growers of California
• AS17381 Williams-Sonoma
• AS14443 Broadridge Financial Solutions, Inc.
• AS27580 CONVERGEONE HOLDINGS, INC.
• AS36040 Google LLC
• AS22768 SYNERGY BROADBAND
• AS18841 Trimble, Inc.
• AS397909 Elk Grove Unified School District
• AS13395 SMART CITY NETWORKS, LIMITED PARTNERSHIP
• AS11681 Integrity Networks
• AS54113 Fastly, Inc.
• AS13335 Cloudflare, Inc.
• AS10309 County of Marin

Routing security

• RPKI: 101 valid, 5 invalid and 16 not-found announcements; 486 ROAs.
• ASPA: none published.
• IRR: 57% of announcements registered; 210 route objects.
• Listed in as-sets: AS-COMCAST-IBONE, AS-COMPUTEARIZONA, AS-COMPUTEAZ, AS11620:AS-PROVIDERS, AS37164:AS-ALL, AS7922:AS-COMCAST-RANS.