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AS399Air Force Systems Networking

United StatesRegistryARIN

As of 22nd October 2026, AS399 (Air Force Systems Networking), a network registered in the United States with ARIN, originates 11 IPv4 prefixes covering 154k addresses. By IPv4 address space that makes it the 1,610th-largest of the 79,663 networks we see originating IPv4, and the 461st-largest of 18,476 in the United States. It is seen behind 1 upstream network, most often AS27066 (United States Department of Defense…). None of its announcements have a valid RPKI ROA. 100% of its routes reach at least 90% of full-feed peers.

At a glance

IPv4 prefixes

11

IPv6 prefixes

0

IPv4 addresses

154k

IPv6 /64s

0

Upstream graph

The networks AS399 is seen behind, one and two hops out, drawn from real AS paths.

AS399Toward the internet core
Upstream graph for AS399: 3 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS399Air Force Systems…This networkAS27066United States Dep…AS721United States Dep…AS27064Defense Informati…

Networks observed one and two hops upstream of AS399 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.

Neighbouring networks

2

adjacent networks

Upstreams
150%
Peers
150%
Downstreams
00%

Networks carrying this one's traffic toward the rest of the internet.

Upstreams of AS399
NetworkCountryRelationshipPathsVantage pts
AS27066United States Department of Defense (DoD)USPeer83977

Prefixes

The largest blocks AS399 originates, widest first.

Largest prefixes originated by AS399
PrefixAddressesVisibility
131.38.0.0/1665.5k77/77
131.49.0.0/1665.5k77/77
143.146.192.0/198.2k77/77
143.156.192.0/198.2k77/77
143.147.80.0/212k77/77
143.157.80.0/212k77/77
132.3.0.0/221k77/77
131.38.120.0/2425677/77
132.7.45.0/2425670/77
132.7.47.0/2425677/77

Routing health

How AS399's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.

RPKI origin validation

  • Valid0.0%0
  • Invalid0.0%0
  • No ROA100.0%11

Propagation

  • Globally propagated90% of full-feed peers or more100.0%11
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 11 prefixes

Recent changes

Announcements that started or stopped since 23rd Sept 2026.

49 announced and 46 withdrawn in all; the most recent are shown.

Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.