AS21508 Comcast Cable Communications, LLC

COMCAST-21508 - Comcast Cable Communications, LLC · registered in the United States

IPv4 addresses689,408142 prefixes · 0.022% of announced IPv4

Rank in United States#134largest network in US by IPv4 space, of 18,338 · 0.05% of US

Rank worldwide#463of 79,396 networks with IPv4

IPv6130 x /32 (8,519,779 x /48)71 prefixes

CountryUnited States18,679 ASNs registered there

Open AS21508 in ASN lookup Look up an IP in this network (23.25.96.1) All networks in United States

IPv4 prefixes

All 142 prefixes, in address order.

23.25.96.0/19
23.25.186.0/23
23.31.96.0/20
24.124.151.0/24
24.124.162.0/23
24.124.248.0/21
24.131.0.0/20
50.73.8.0/22
50.73.224.0/20
50.77.72.0/21
50.78.232.0/21
50.184.128.0/19
50.186.32.0/19
50.189.192.0/18
50.193.246.0/23
50.199.16.0/20
50.204.101.0/24
50.205.217.0/24
50.210.0.0/20
50.211.32.0/19
50.215.32.0/19
50.216.229.0/24
50.217.1.0/24
50.217.207.0/24
50.218.47.0/24
50.228.113.0/24
50.229.113.0/24
50.229.114.0/24
50.235.34.0/24
50.240.80.0/20
50.242.32.0/19
50.245.224.0/19
50.251.112.0/20
50.253.208.0/20
64.139.66.0/24
64.139.70.0/24
64.139.79.0/24
64.139.90.0/24
66.208.224.0/23
66.208.230.0/24
66.208.234.0/24
67.163.96.0/19
67.166.160.0/19
67.172.192.0/19
67.174.64.0/20
67.187.0.0/19
68.85.70.0/23
68.85.214.0/24
68.85.226.0/24
68.86.14.0/24
68.86.24.0/24
68.86.124.0/22
68.86.172.0/22
68.86.200.0/24
68.87.3.0/24
69.139.165.0/24
69.139.186.0/24
69.139.206.0/24
69.139.223.0/24
69.241.48.0/23
69.241.85.0/24
69.243.208.0/20
69.244.224.0/20
69.252.18.0/23
70.88.24.0/23
70.88.164.0/24
70.88.168.0/23
70.88.184.0/21
70.89.232.0/21
70.91.162.0/24
71.24.32.0/19
71.56.160.0/19
71.57.192.0/19
71.62.0.0/16
71.63.0.0/17
71.197.0.0/20
71.206.128.0/18
71.207.128.0/19
74.92.186.0/23
74.92.255.0/24
74.93.116.0/22
74.94.208.0/21
74.95.96.0/22
75.75.0.0/18
75.75.64.0/21
75.75.80.0/20
75.75.96.0/19
75.144.34.0/23
75.145.196.0/22
75.145.204.0/22
75.145.240.0/21
75.146.16.0/20
75.146.87.0/24
75.150.48.0/20
76.26.64.0/19
76.27.160.0/19
76.104.0.0/17
76.111.176.0/20
76.120.192.0/18
76.123.0.0/18
96.75.192.0/19
96.82.0.0/20
96.82.24.0/21
96.84.224.0/20
96.85.32.0/20
96.89.0.0/19
96.94.208.0/20
96.96.176.0/21
96.108.106.0/23
96.108.129.0/24
96.108.130.0/23
96.108.140.0/23
96.109.65.0/24
96.109.165.0/24
96.109.200.0/22
96.110.123.0/24
96.110.200.0/22
96.114.56.0/23
96.124.244.0/22
96.208.0.0/21
96.216.16.0/22
96.216.88.0/22
141.104.0.0/16
157.240.147.0/24
157.240.148.0/24
162.151.58.0/23
162.151.162.0/23
162.151.255.0/24
173.14.112.0/20
173.14.193.0/24
173.15.192.0/20
173.163.192.0/20
173.167.32.0/20
173.167.48.0/21
173.167.80.0/22
173.242.174.0/24
174.53.64.0/19
174.179.0.0/16
184.115.0.0/18
198.90.112.0/22
204.194.47.0/24
205.223.19.0/24

IPv6 prefixes

All 71 prefixes.

2001:558:180::/44
2001:558:230::/44
2001:558:501e::/48
2001:558:6023::/48
2001:558:6036::/48
2001:558:701a::/48
2001:558:a006::/48
2001:558:fe30::/48
2001:559:8a::/48
2001:559:c0::/48
2001:559:f7::/48
2001:559:220::/48
2001:559:243::/48
2001:559:280::/48
2001:559:37d::/48
2001:559:3ac::/48
2001:559:3b9::/48
2001:559:3c8::/48
2001:559:40a::/48
2001:559:49a::/47
2001:559:53c::/48
2001:559:5c9::/48
2001:559:5db::/48
2001:559:72b::/48
2001:559:73c::/48
2001:559:788::/48
2001:559:78a::/48
2001:559:79d::/48
2001:559:79e::/48
2001:559:7a7::/48
2001:559:7db::/48
2001:559:804c::/48
2001:559:81bf::/48
2001:559:81d7::/48
2001:559:81d8::/48
2001:559:8201::/48
2001:559:82fd::/48
2001:559:833e::/48
2001:559:8416::/48
2001:559:841c::/48
2001:559:8445::/48
2001:559:8535::/48
2001:559:85c1::/48
2001:559:85ff::/48
2001:559:8604::/48
2001:559:871a::/48
2001:559:875f::/48
2001:559:8773::/48
2001:559:87b2::/48
2001:559:c071::/48
2001:559:c0f6::/47
2001:559:c10a::/48
2001:559:c174::/48
2001:559:c1a5::/48
2001:559:c1ca::/48
2001:559:c28f::/48
2001:559:c290::/48
2001:559:c2a7::/48
2001:559:c344::/48
2001:559:c3e9::/48
2001:559:c458::/48
2001:559:c45f::/48
2001:559:c460::/48
2001:559:c4db::/48
2001:559:c4f6::/48
2001:559:c515::/48
2001:559:c538::/48
2601:5c0::/26
2603:25c0::/26
2603:3021::/32
2603:308a::/32

Other ASNs named Comcast Cable Communications, LLC

37 other networks use the same organisation name; together with AS21508 they announce 68,427,008 IPv4 addresses. Largest 30 shown.

ASNNameIPv4 addresses

AS7922COMCAST-7922 - Comcast Cable Communications, LLC US42,195,200

AS33491COMCAST-33491 - Comcast Cable Communications, LLC US3,142,144

AS33651CMCS - Comcast Cable Communications, LLC US2,267,136

AS33668CMCS - Comcast Cable Communications, LLC US1,857,536

AS33652CMCS - Comcast Cable Communications, LLC US1,759,744

AS20214COMCAST-20214 - Comcast Cable Communications, LLC US1,720,832

AS7016CCCH-3 - Comcast Cable Communications, LLC US1,577,984

AS33657CMCS - Comcast Cable Communications, LLC US1,553,408

AS7725COMCAST-7725 - Comcast Cable Communications, LLC US1,466,624

AS33287COMCAST-33287 - Comcast Cable Communications, LLC US1,312,512

AS33659CMCS - Comcast Cable Communications, LLC US1,147,136

AS22909COMCAST-22909 - Comcast Cable Communications, LLC US1,075,968

AS13367COMCAST-13367 - Comcast Cable Communications, LLC US1,005,056

AS33667CMCS - Comcast Cable Communications, LLC US999,936

AS33490COMCAST-33490 - Comcast Cable Communications, LLC US852,480

AS22258COMCAST-22258 - Comcast Cable Communications, LLC US664,064

AS33489COMCAST-33489 - Comcast Cable Communications, LLC US647,936

AS33661CMCS - Comcast Cable Communications, LLC US630,528

AS33660CMCS - Comcast Cable Communications, LLC US621,824

AS33654CMCS - Comcast Cable Communications, LLC US337,920

AS33666CMCS - Comcast Cable Communications, LLC US247,296

AS33656CMCS - Comcast Cable Communications, LLC US165,632

AS33653CMCS - Comcast Cable Communications, LLC US146,944

AS33665CMCS - Comcast Cable Communications, LLC US112,128

AS33655CMCS - Comcast Cable Communications, LLC US89,600

AS36733DNEO-OSP7 - Comcast Cable Communications, LLC US58,880

AS7015COMCAST-7015 - Comcast Cable Communications, LLC US46,080

AS36732COMCAST-36732 - Comcast Cable Communications, LLC US24,064

AS33662CMCS - Comcast Cable Communications, LLC US3,840

AS33650COMCAST-33650 - Comcast Cable Communications, LLC US3,584

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IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources