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AS3527National Institutes of Health

United StatesRegistryARINTypeContent

As of 23rd October 2026, AS3527 (National Institutes of Health), a content network registered in the United States with ARIN, originates 15 IPv4 prefixes covering 346k addresses and 1 IPv6 prefix. By IPv4 address space that makes it the 879th-largest of the 79,652 networks we see originating IPv4, and the 218th-largest of 18,475 in the United States. It is seen behind 2 upstream networks, most often AS19050 (U.S. Department of Health & Human…) and AS10886 (University of Maryland), and in front of 1 downstream network. 81% of its announcements have a valid RPKI ROA, and none are RPKI-invalid. 81% of its routes reach at least 90% of full-feed peers, and 3 prefixes are also originated by another network.

At a glance

IPv4 prefixes

15

IPv6 prefixes

1

IPv4 addresses

346k

IPv6 /64s

2.1M

Upstream graph

The networks AS3527 is seen behind, one and two hops out, drawn from real AS paths.

AS3527Toward the internet core
Upstream graph for AS3527: 5 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS3527National Institut…This networkAS10886University of Mar…AS19050U.S. Department o…AS1299Arelion (fka. Tel…AS6461Zayo BandwidthAS15029U.S. Department o…

Networks observed one and two hops upstream of AS3527 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

6

adjacent networks

Upstreams
233%
Peers
350%
Downstreams
117%

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

Upstreams of AS3527
NetworkCountryRelationshipPathsVantage pts
AS19050U.S. Department of Health & Human ServicesUSPeer885140
AS10886University of MarylandUSPeer18518

Prefixes

The largest blocks AS3527 originates, widest first.

Largest prefixes originated by AS3527
PrefixAddressesVisibility
128.231.0.0/1665.5k77/77
137.187.0.0/1665.5k77/77
156.40.0.0/1665.5k77/77
157.98.0.0/1665.5k77/77
165.112.0.0/1665.5k77/77
162.99.224.0/198.2k77/77
165.112.0.0/204.1k2/77
165.112.0.0/212k2/77
165.112.136.0/212k2/77
192.231.146.0/2351277/77

Routing health

How AS3527'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

  • Valid81.3%13
  • Invalid0.0%0
  • No ROA18.8%3

Propagation

  • Globally propagated90% of full-feed peers or more81.3%13
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%18.8%3

Prefix sizes

IPv4 — 15 prefixes

IPv6 — 1 prefixes

  • /432.1M × /64100.0%1

Recent changes

Announcements that started or stopped since 23rd Sept 2026.

No announcement by AS3527 started or stopped in this period.

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