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AS721

AS721 is DoD Network Information Center.

Last updated 3 Nov 2026 from DB-IP ASN Lite (2026-11-01) and RIR statistics (4 Nov 2026)

Short answer

AS721 belongs to DoD Network Information Center. DB-IP Lite attributes 28,085,504 IPv4 addresses in 2,197 ranges and 3 IPv6 ranges to it, all or nearly all of the IPv4 space in United States. The number is registered with ARIN in United States.

Facts for AS721
Operator (DB-IP)DoD Network Information Center
IPv4 addresses28,085,504
IPv4 ranges2,197
IPv6 ranges3
RegistryARIN
Registered—
Registry countryUnited States (US)

Does it publish a geofeed?

We haven’t checked this network’s registry records for a geofeed yet. The Truth Check looks for one live for any address you test.

Shared addresses (CGNAT)

DoD Network Information Center hasn’t been documented as using carrier-grade NAT in a source we could check. To see whether your own connection is behind it, compare your router’s address on the CGNAT check.

IPv6

DB-IP lists 3 IPv6 ranges for AS721, so customers can get IPv6 addresses, which databases place separately from IPv4.

Where its IPv4 space is used, according to DB-IP

US100%
JP0.23%

Share of the network’s IPv4 addresses by DB-IP Country Lite. IP Geolocation by DB-IP.

IP ranges

RangeAs CIDRAddresses
6.16.172.0 – 6.16.174.2556.16.172.0/23, 6.16.174.0/24768
6.64.181.0 – 6.64.181.2556.64.181.0/24256
55.0.0.0 – 55.0.255.25555.0.0.0/1665,536
55.2.242.0 – 55.2.242.25555.2.242.0/24256
55.2.249.0 – 55.2.249.25555.2.249.0/24256
55.2.251.0 – 55.2.251.25555.2.251.0/24256
55.2.255.0 – 55.2.255.25555.2.255.0/24256
55.7.249.0 – 55.7.255.25555.7.249.0/24, 55.7.250.0/23 …1,792
55.9.0.0 – 55.9.255.25555.9.0.0/1665,536
55.12.0.0 – 55.12.255.25555.12.0.0/1665,536
55.13.220.0 – 55.14.255.25555.13.220.0/22, 55.13.224.0/19 …74,752
55.21.0.0 – 55.21.255.25555.21.0.0/1665,536
55.27.210.0 – 55.27.210.25555.27.210.0/24256
55.27.216.0 – 55.27.216.25555.27.216.0/24256
55.27.218.0 – 55.27.218.25555.27.218.0/24256
55.27.220.0 – 55.27.220.25555.27.220.0/24256
55.27.222.0 – 55.27.255.25555.27.222.0/23, 55.27.224.0/198,704
55.29.0.0 – 55.29.255.25555.29.0.0/1665,536
55.31.0.0 – 55.31.255.25555.31.0.0/1665,536
55.33.0.0 – 55.33.255.25555.33.0.0/1665,536
55.57.0.0 – 55.57.255.25555.57.0.0/1665,536
55.66.0.0 – 55.66.255.25555.66.0.0/1665,536
55.80.0.0 – 55.81.255.25555.80.0.0/15131,072
55.101.0.0 – 55.179.143.25555.101.0.0/16, 55.102.0.0/15 …5,148,672
55.179.146.0 – 55.179.229.25555.179.146.0/23, 55.179.148.0/22 …21,504
55.179.237.0 – 55.187.255.25555.179.237.0/24, 55.179.238.0/23 …529,152
55.189.37.0 – 55.189.39.25555.189.37.0/24, 55.189.38.0/23768
55.189.48.0 – 55.189.57.25555.189.48.0/21, 55.189.56.0/232,560
55.189.60.0 – 55.189.63.25555.189.60.0/221,024
55.189.97.0 – 55.189.179.25555.189.97.0/24, 55.189.98.0/23 …21,248
55.189.181.0 – 55.190.1.25555.189.181.0/24, 55.189.182.0/23 …19,712
55.190.4.0 – 55.190.7.25555.190.4.0/221,024
55.190.9.0 – 55.190.79.25555.190.9.0/24, 55.190.10.0/23 …18,176
55.190.81.0 – 55.190.81.25555.190.81.0/24256
55.190.83.0 – 55.190.83.25555.190.83.0/24256
55.190.86.0 – 55.190.87.25555.190.86.0/23512
55.190.89.0 – 55.190.96.25555.190.89.0/24, 55.190.90.0/23 …2,048
55.190.98.0 – 55.190.199.25555.190.98.0/23, 55.190.100.0/22 …26,112
55.190.201.0 – 55.190.253.25555.190.201.0/24, 55.190.202.0/23 …13,568
55.190.255.0 – 55.190.255.25555.190.255.0/24256
55.192.0.0 – 55.193.255.25555.192.0.0/15131,072
55.197.0.0 – 55.201.241.25555.197.0.0/16, 55.198.0.0/15 …324,096
55.201.243.0 – 55.209.99.25555.201.243.0/24, 55.201.244.0/22 …487,680
55.209.101.0 – 55.209.199.25555.209.101.0/24, 55.209.102.0/23 …25,344
55.209.204.0 – 55.224.0.25555.209.204.0/22, 55.209.208.0/20 …931,072
55.224.2.0 – 55.224.6.25555.224.2.0/23, 55.224.4.0/23 …1,280
55.224.9.0 – 55.224.11.25555.224.9.0/24, 55.224.10.0/23768
55.224.32.0 – 55.224.63.25555.224.32.0/198,192
55.224.81.0 – 55.224.81.25555.224.81.0/24256
55.224.83.0 – 55.224.85.25555.224.83.0/24, 55.224.84.0/23768
2608:120:: – 2608:120:1:ffff:ffff:ffff:ffff:ffff2608:120::/47IPv6
2608:120:3:: – 2608:120:b:ffff:ffff:ffff:ffff:ffff2608:120:3::/48IPv6
2608:120:d:: – 2608:121:ffff:ffff:ffff:ffff:ffff:ffff2608:120:d::/48IPv6
Showing 50 of 2,197 IPv4 and 3 of 3 IPv6 ranges All ranges (CSV)

IP Geolocation by DB-IP, ASN Lite, CC BY 4.0.

Using an address from this network? See which sources agree on where it is.

Sources

  1. DB-IP IP to ASN Lite (CC BY 4.0) · checked 3 Nov 2026
  2. NRO RIR delegated-extended statistics · checked 5 Nov 2026