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AS21508
COMCAST-21508

AS21508 announces 689,408 IPv4 addresses across 135 routed ranges, registered in US. Figures come from the public global routing table and are refreshed daily.

689K addressesIPv4 space announced
135Routed ranges
USRegistry country

Is AS21508 datacenter space?

Not according to the nine cloud and CDN providers whose published range lists we track. That is a statement about those specific lists, not proof the space is residential — plenty of hosting companies never publish machine-readable ranges, and this AS may well be one of them.

The reliable way to classify a specific address is to check it directly rather than to infer from the AS. The free lookup tool returns live tunnel and datacenter signals for any address.

What an AS number does and does not tell you

An autonomous system number identifies who announces a block of addresses to the internet's routing table. It is an organisational fact, and a durable one — useful for attributing traffic to a hosting company, a carrier, or a university.

It is not a risk signal. A residential ISP's AS carries the household traffic of millions of ordinary customers and, at the same time, whatever residential proxy exits have been installed on those customers' devices. A hosting AS carries scrapers and legitimate server-to-server integrations in the same ranges. Scoring an address on the reputation of its AS produces exactly the false positives that make fraud tooling untrustworthy.

Sentinel does not feed AS names or routing data into its risk score. Tunnel detection comes from live network intelligence, and the dch signal comes from provider-published ranges. This directory exists to answer "who announces this address," which is a different and genuinely useful question.

Announced IPv4 ranges

All 135 announced ranges.

Range startRange endAddresses
23.25.96.023.25.127.2558,192
23.25.186.023.25.187.255512
23.31.96.023.31.111.2554,096
24.124.151.024.124.151.255256
24.124.162.024.124.163.255512
24.124.248.024.124.255.2552,048
24.131.0.024.131.15.2554,096
50.73.8.050.73.11.2551,024
50.73.224.050.73.239.2554,096
50.77.72.050.77.79.2552,048
50.78.232.050.78.239.2552,048
50.184.128.050.184.159.2558,192
50.186.32.050.186.63.2558,192
50.189.192.050.189.255.25516,384
50.193.246.050.193.247.255512
50.199.16.050.199.31.2554,096
50.204.101.050.204.101.255256
50.205.217.050.205.217.255256
50.210.0.050.210.15.2554,096
50.211.32.050.211.63.2558,192
50.215.32.050.215.63.2558,192
50.216.229.050.216.229.255256
50.217.1.050.217.1.255256
50.217.207.050.217.207.255256
50.218.47.050.218.47.255256
50.228.113.050.228.113.255256
50.229.113.050.229.114.255512
50.235.34.050.235.34.255256
50.240.80.050.240.95.2554,096
50.242.32.050.242.63.2558,192
50.245.224.050.245.255.2558,192
50.251.112.050.251.127.2554,096
50.253.208.050.253.223.2554,096
64.139.66.064.139.66.255256
64.139.70.064.139.70.255256
64.139.79.064.139.79.255256
64.139.90.064.139.90.255256
66.208.224.066.208.225.255512
66.208.230.066.208.230.255256
66.208.234.066.208.234.255256
67.163.96.067.163.127.2558,192
67.166.160.067.166.191.2558,192
67.172.192.067.172.223.2558,192
67.174.64.067.174.79.2554,096
67.187.0.067.187.31.2558,192
68.85.70.068.85.71.255512
68.85.214.068.85.214.255256
68.85.226.068.85.226.255256
68.86.14.068.86.14.255256
68.86.24.068.86.24.255256
68.86.124.068.86.127.2551,024
68.86.172.068.86.175.2551,024
68.86.200.068.86.200.255256
68.87.3.068.87.3.255256
69.139.165.069.139.165.255256
69.139.186.069.139.186.255256
69.139.206.069.139.206.255256
69.139.223.069.139.223.255256
69.241.48.069.241.49.255512
69.241.85.069.241.85.255256
69.243.208.069.243.223.2554,096
69.244.224.069.244.239.2554,096
69.252.18.069.252.19.255512
70.88.24.070.88.25.255512
70.88.164.070.88.164.255256
70.88.168.070.88.169.255512
70.88.184.070.88.191.2552,048
70.89.232.070.89.239.2552,048
70.91.162.070.91.162.255256
71.24.32.071.24.63.2558,192
71.56.160.071.56.191.2558,192
71.57.192.071.57.223.2558,192
71.62.0.071.63.127.25598,304
71.197.0.071.197.15.2554,096
71.206.128.071.206.191.25516,384
71.207.128.071.207.159.2558,192
74.92.186.074.92.187.255512
74.92.255.074.92.255.255256
74.93.116.074.93.119.2551,024
74.94.208.074.94.215.2552,048
74.95.96.074.95.99.2551,024
75.75.0.075.75.71.25518,432
75.75.80.075.75.127.25512,288
75.144.34.075.144.35.255512
75.145.196.075.145.199.2551,024
75.145.204.075.145.207.2551,024
75.145.240.075.145.247.2552,048
75.146.16.075.146.31.2554,096
75.146.87.075.146.87.255256
75.150.48.075.150.63.2554,096
76.26.64.076.26.95.2558,192
76.27.160.076.27.191.2558,192
76.104.0.076.104.127.25532,768
76.111.176.076.111.191.2554,096
76.120.192.076.120.255.25516,384
76.123.0.076.123.63.25516,384
96.75.192.096.75.223.2558,192
96.82.0.096.82.15.2554,096
96.82.24.096.82.31.2552,048
96.84.224.096.84.239.2554,096

Check a specific address

The AS tells you who announces a range. Whether one address inside it is currently a tunnel is a live question, answered per address — for example 23.25.96.0, the first address in this AS's announced space. The free lookup tool takes any address, and the IP intelligence hub explains what each signal means.

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