Home / ASN Directory / AS3371

AS3371
MCI-ASN

AS3371 announces 1,154,304 IPv4 addresses across 71 routed ranges, registered in US. Figures come from the public global routing table and are refreshed daily.

1.2M addressesIPv4 space announced
71Routed ranges
USRegistry country

Is AS3371 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 71 announced ranges.

Range startRange endAddresses
63.39.0.063.39.159.25540,960
63.39.208.063.39.239.2558,192
63.91.192.063.91.255.25516,384
69.96.0.069.96.15.2554,096
69.103.0.069.103.255.25565,536
100.5.64.0100.5.127.25516,384
108.37.128.0108.37.255.25532,768
142.77.8.0142.77.11.2551,024
142.77.72.0142.77.95.2556,144
153.39.96.0153.39.255.25540,960
159.98.0.0159.98.71.25518,432
159.98.80.0159.98.103.2556,144
159.98.116.0159.98.255.25535,840
162.47.152.0162.47.155.2551,024
165.122.48.0165.122.63.2554,096
166.32.32.0166.32.47.2554,096
166.32.64.0166.32.127.25516,384
166.32.176.0166.32.207.2558,192
166.32.208.0166.32.239.2558,192
166.33.128.0166.33.159.2558,192
166.33.208.0166.34.63.25528,672
166.35.0.0166.35.127.25532,768
166.36.32.0166.36.79.25512,288
166.36.96.0166.36.255.25540,960
166.37.64.0166.37.95.2558,192
166.37.128.0166.37.193.25516,896
166.37.196.0166.37.199.2551,024
166.37.224.0166.37.231.2552,048
166.38.0.0166.38.33.2558,704
166.38.35.0166.38.37.255768
166.38.39.0166.38.51.2553,328
166.38.54.0166.38.75.2555,632
166.38.80.0166.38.95.2554,096
166.38.128.0166.38.131.2551,024
166.38.134.0166.38.135.255512
166.38.138.0166.38.159.2555,632
166.38.177.0166.38.177.255256
166.38.184.0166.38.187.2551,024
166.38.240.0166.38.255.2554,096
166.39.16.0166.39.63.25512,288
166.39.96.0166.39.115.2555,120
166.39.160.0166.39.207.25512,288
166.39.224.0166.40.111.25536,864
166.40.128.0166.40.160.2558,448
166.40.168.0166.40.168.255256
166.40.170.0166.40.171.255512
166.40.174.0166.40.215.25510,752
166.40.224.0166.41.15.25512,288
166.41.64.0166.41.143.25520,480
166.41.208.0166.43.143.255114,688
166.43.192.0166.43.255.25516,384
166.44.0.0166.44.239.25561,440
166.44.242.0166.44.251.2552,560
166.44.252.0166.46.111.25595,232
166.46.128.0166.46.159.2558,192
166.46.208.0166.46.223.2554,096
166.46.240.0166.47.143.25540,960
166.47.176.0166.47.239.25516,384
166.50.0.0166.50.79.25520,480
166.50.96.0166.50.255.25540,960
166.56.0.0166.56.31.2558,192
166.56.128.0166.56.247.25530,720
166.56.250.0166.56.255.2551,536
166.58.48.0166.58.127.25520,480
166.58.144.0166.58.223.25520,480
166.58.240.0166.58.247.2552,048
199.170.112.0199.170.112.255256
199.202.116.0199.202.116.255256
205.150.160.0205.150.160.255256
205.150.162.0205.150.162.255256
209.154.224.0209.154.255.2558,192

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 63.39.0.0, 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.

Check a specific address in this AS.
Live VPN, proxy, Tor, and datacenter signals. Free tier, 1,000 requests/hour.
Get a free API key →
All ASNs Example: 63.39.0.0 IP intelligence Free IP lookup Hosting provider ranges Residential proxy networks TLS fingerprinting