subnet.im

AS21700Neptune Networks, LLC

United StatesRegistryARINTypeCarrier

As of 26th September 2026, AS21700 (Neptune Networks, LLC), a transit carrier registered in the United States with ARIN, originates 7 IPv4 prefixes covering 2.8k addresses and 2 IPv6 prefixes. By IPv4 address space that makes it the 22,343rd-largest of the 79,516 networks we see originating IPv4, and the 5,682nd-largest of 18,424 in the United States. It is seen behind 13 upstream networks, most often AS6939 (Hurricane Electric LLC) and AS3257 (GTT Communications Inc.), and in front of 54 downstream networks. Every one of its announcements has a valid RPKI ROA, and none are RPKI-invalid. 100% of its routes reach at least 90% of full-feed peers.

At a glance

IPv4 prefixes

7

IPv6 prefixes

2

IPv4 addresses

2.8k

IPv6 /64s

4.4B

Upstream graph

The networks AS21700 is seen behind, one and two hops out, drawn from real AS paths.

AS21700Toward the internet core
Upstream graph for AS21700: 12 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS21700Neptune Networks,…This networkAS174Cogent Communicat…AS3257GTT Communication…AS6939Hurricane Electri…AS13030Init7 (Switzerlan…AS14537Continent 8 LLCAS151326DCConnect Communi…AS6667Elisa OyjAS398465Rackdog LLCAS1299Arelion (fka. Tel…AS18106Viewqwest Pte LtdAS20130Depaul UniversityAS56662Marcin Gondek

Networks observed one and two hops upstream of AS21700 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

261

adjacent networks

Upstreams
135%
Peers
19474%
Downstreams
5421%

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

Upstreams of AS21700
NetworkCountryRelationshipPathsVantage pts
AS6939Hurricane Electric LLCUSPeer2,73762
AS3257GTT Communications Inc.USPeer1,64275
AS174Cogent Communications, LLCUSPeer1,28487
AS13030Init7 (Switzerland) Ltd.CHPeer2785
AS14537Continent 8 LLCUSPeer2164
AS9002RETN LimitedGBPeer1226
AS7195EdgeUnoCOPeer1092
AS49544i3D.net B.VNLPeer982
AS18106Viewqwest Pte LtdSGPeer662
AS1000LINK AMERICANUSPeer511

Prefixes

The largest blocks AS21700 originates, widest first.

Largest prefixes originated by AS21700
PrefixAddressesVisibility
209.151.100.0/221k80/81
172.82.22.0/2351280/81
23.157.160.0/2425680/81
157.254.142.0/2425680/81
192.109.165.0/2425680/81
216.74.121.0/2425680/81
216.126.57.0/2425680/81
2606:f1c0::/324.3B × /6464/64
2602:fe2e::/37134M × /6464/64

Routing health

How AS21700'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

  • Valid100.0%9
  • Invalid0.0%0
  • No ROA0.0%0

Propagation

  • Globally propagated90% of full-feed peers or more100.0%9
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 7 prefixes

IPv6 — 2 prefixes

  • /324.3B × /6450.0%1
  • /37134M × /6450.0%1

Recent changes

Announcements that started or stopped since 28th Aug 2026.

  • Withdrawn159.148.114.0/2421st Sept 2026

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