Country
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ASN LANDING PAGE
AS21508
COMCAST-21508 - Comcast Cable Communications, LLC
Last updated · Jul 20, 2026
Total prefixes
78
IPv4 prefixes
17
IPv6 prefixes
61
ASN summary
How to read the scale of AS21508
COMCAST-21508 - Comcast Cable Communications, LLC currently reports 78 prefixes and 41 upstream, downstream, or peer relationships. These counts describe the current dataset; they do not by themselves prove network quality, reach, or service use.
What can an ASN page answer?
An ASN page shows the public organization label, country or region, BGP prefixes, and available peer and upstream relationships. It adds network context but cannot confirm a website host, physical facility, security status, or service quality.
How should you read the organization and region fields?
COMCAST-21508 - Comcast Cable Communications, LLC is currently associated with an unknown region. These values come from public network sources and are useful lookup clues; an organization label, registration region, and actual service location may differ.
How should you verify the AS21508 result?
The page shows ASN data returned by the current upstream query; interpret it with the update time. Open representative IP pages from the same network and compare prefixes, source labels, and query times. Verify operator or service claims with the relevant registry or network operator.
How to verify this ASN result
AS21508 ASN lookupAS21508 BGPAS21508 peersAS21508 prefixesAS21508 upstreamsCOMCAST-21508 - Comcast Cable Communications, LLC ASN
Upstreams
Detailed data for this ASN is not available right now.
Downstreams
AS13335
AS13335
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AS54113
AS54113
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AS400114
AS400114
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AS36364
AS36364
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AS54883
AS54883
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AS396083
AS396083
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AS36040
AS36040
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AS40641
AS40641
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AS32540
AS32540
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AS54219
AS54219
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AS15297
AS15297
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AS399938
AS399938
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AS402549
AS402549
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AS399099
AS399099
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AS15173
AS15173
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AS11739
AS11739
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AS394276
AS394276
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AS36244
AS36244
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AS14583
AS14583
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AS395772
AS395772
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AS19923
AS19923
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AS397039
AS397039
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AS394058
AS394058
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AS397483
AS397483
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AS63468
AS63468
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AS393613
AS393613
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AS18773
AS18773
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AS10794
AS10794
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AS22274
AS22274
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AS46643
AS46643
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AS396452
AS396452
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AS19404
AS19404
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AS395527
AS395527
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AS399607
AS399607
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AS23209
AS23209
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AS30299
AS30299
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AS62971
AS62971
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AS11679
AS11679
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AS393591
AS393591
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AS397190
AS397190
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Peers
Prefix inventory
| Prefix | Name | Country |
|---|---|---|
| 141.104.0.0/16 | AS21508 | — |
| 157.240.147.0/24 | AS21508 | — |
| 157.240.148.0/24 | AS21508 | — |
| 173.242.174.0/24 | AS21508 | — |
| 198.90.112.0/22 | AS21508 | — |
| 2001:559:220::/48 | AS21508 | — |
| 2001:559:243::/48 | AS21508 | — |
| 2001:559:280::/48 | AS21508 | — |
| 2001:559:37d::/48 | AS21508 | — |
| 2001:559:3ac::/48 | AS21508 | — |
| 2001:559:3b9::/48 | AS21508 | — |
| 2001:559:3c8::/48 | AS21508 | — |
| 2001:559:40a::/48 | AS21508 | — |
| 2001:559:49a::/48 | AS21508 | — |
| 2001:559:49b::/48 | AS21508 | — |
| 2001:559:53c::/48 | AS21508 | — |
| 2001:559:5c9::/48 | AS21508 | — |
| 2001:559:5db::/48 | AS21508 | — |
| 2001:559:72b::/48 | AS21508 | — |
| 2001:559:73c::/48 | AS21508 | — |
| 2001:559:788::/48 | AS21508 | — |
| 2001:559:78a::/48 | AS21508 | — |
| 2001:559:79d::/48 | AS21508 | — |
| 2001:559:79e::/48 | AS21508 | — |
| 2001:559:7a7::/48 | AS21508 | — |
| 2001:559:7db::/48 | AS21508 | — |
| 2001:559:804c::/48 | AS21508 | — |
| 2001:559:81bf::/48 | AS21508 | — |
| 2001:559:81d7::/48 | AS21508 | — |
| 2001:559:81d8::/48 | AS21508 | — |
| 2001:559:8201::/48 | AS21508 | — |
| 2001:559:82fd::/48 | AS21508 | — |
| 2001:559:833e::/48 | AS21508 | — |
| 2001:559:8416::/48 | AS21508 | — |
| 2001:559:841c::/48 | AS21508 | — |
| 2001:559:8445::/48 | AS21508 | — |
| 2001:559:8535::/48 | AS21508 | — |
| 2001:559:85c1::/48 | AS21508 | — |
| 2001:559:85ff::/48 | AS21508 | — |
| 2001:559:8604::/48 | AS21508 | — |
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Related lookups and next steps
Frequently asked questions about this ASN page
What does AS21508 represent?
AS21508 is an autonomous system number. The current source associates it with COMCAST-21508 - Comcast Cable Communications, LLC and the region field an unknown region; those values add network context but do not prove a specific service, physical location, or quality level.
What are peers, upstreams, and prefixes useful for on the AS21508 page?
They help explain the scale, interconnection depth, and route structure of AS21508. Richer peering and upstream data often indicate broader network reach, but they should still be interpreted together with prefixes and related IP landing pages.
What should you do after reviewing AS21508?
Open a concrete IP page to check how the address maps into AS21508, then compare the prefix, source labels, and query time. Verify operator or service claims with the relevant registry or network operator.
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