Autonomous System

AS340 United States Department of Defense (DoD)

GovernmentActiveUnited StatesARIN

AS340 (DNIC-ASBLK-00306-00371) is a government network operated by United States Department of Defense (DoD) in United States, registered with ARIN. It has 6 IPv4 prefixes with 197,376 addresses and 1 IPv6 prefix, which makes it the 1,325th largest of 82,200 active autonomous systems by IPv4 space.

IPv4 addresses197,376in 6 prefixes
IPv6 prefixes1≈ 3.1 × 10²⁶ addresses
Size rank#1,325of 82,200 active ASNs
Abuser scoreVery Lowunder 0.01% of its addresses flagged · method

Details

OrganizationUnited States Department of Defense (DoD)
AS nameDNIC-ASBLK-00306-00371
Websitedefense.gov
Country United States (US)
Network typeGovernment
RegistryARIN
Abuse contactdisa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil
Registered1989-06-30
Last updated2025-09-12

IPv4 prefixes

6 prefixes · 197,376 addresses
NetworkAddressesFirst – last address
55.40.0.0/1665,53655.40.0.0 – 55.40.255.255
55.73.0.0/1665,53655.73.0.0 – 55.73.255.255
55.86.0.0/1665,53655.86.0.0 – 55.86.255.255
55.40.242.0/2425655.40.242.0 – 55.40.242.255
55.40.255.0/2425655.40.255.0 – 55.40.255.255
55.86.50.0/2425655.86.50.0 – 55.86.50.255

IPv6 prefixes

1 prefix
  • 2608:14b:4500::/40

Query AS340 with the API

The ASN lookup returns everything on this page as JSON, including every prefix. ASN lookups need an API key: a free account comes with 1,000 requests a day. 

curl "https://api.ipapi.is/?q=AS340&key=YOUR_API_KEY"

Any address in its prefixes resolves to AS340, with or without a key:

curl "https://api.ipapi.is/?q=55.40.0.1"

Other networks of United States Department of Defense (DoD)

6 of 108
AS749 United States Department of Defense (DoD)227,464,192 IPv4 addressesAS721 United States Department of Defense (DoD)73,070,080 IPv4 addressesAS56 United States Department of Defense (DoD)8,082,944 IPv4 addressesAS306 United States Department of Defense (DoD)4,666,880 IPv4 addressesAS668 United States Department of Defense (DoD)2,558,464 IPv4 addressesAS5972 United States Department of Defense (DoD)2,298,624 IPv4 addresses

Largest networks in United States

AS749 United States Department of Defense (DoD)227,464,192 IPv4 addressesAS16509 Amazon.com, Inc.218,038,784 IPv4 addressesAS7018 AT&T Enterprises, LLC117,262,080 IPv4 addressesAS8075 Microsoft Corporation81,463,040 IPv4 addressesAS721 United States Department of Defense (DoD)73,070,080 IPv4 addressesAS7922 Comcast Cable Communications, LLC68,336,896 IPv4 addresses