asn.dev

Observed topology

AS21700 NEPTUNE-NETWORKS

Unclassified ARIN

Upstreams 7 carry this network
Downstreams 52 this network carries
Adjacent (IPv4) 40
Adjacent (IPv6) 43
Upstream graph Who carries AS21700, and who carries them, drawn as a map up to the transit-free core. 1 exchange Where AS21700 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS21700: the AS immediately before it in a routing path. Ranked by how many paths showed the relationship, which reflects how widely it is used, not how much traffic crosses it.

ASNetworkTypeFamiliesPaths seen
AS174Cogent Communications, LLCTransitIPv4 IPv6181
AS3257GTT Communications Inc.TransitIPv4147
AS6939Hurricane Electric LLCTransitIPv4 IPv6123
AS24482SG.GSHostingIPv4 IPv69
AS17639Converge ICT Solutions Inc.UnclassifiedIPv47
AS9002RETN LimitedUnclassifiedIPv64
AS13030Init7 (Switzerland) Ltd.HostingIPv62

Transit

Downstream networks

All 52

Networks for which AS21700 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS400967Assured NetworksHostingIPv4 IPv6403
AS19949FNFISPUnclassifiedIPv4399
AS53727Penguin NetworksUnclassifiedIPv4 IPv6299
AS401363Lyncross LLCUnclassifiedIPv4 IPv6170
AS63229Nocturnal NetworksUnclassifiedIPv4 IPv6150
AS53343sc NetworkUnclassifiedIPv4 IPv6149
AS961Achieve Wireless IncUnclassifiedIPv4 IPv6131
AS18470GraceWorks, LLCUnclassifiedIPv4 IPv6130
AS203943ALEXANDER NICHOLSONUnclassifiedIPv6111
AS400550Suburban Marine, Inc.UnclassifiedIPv6111

All 52 downstreams →

Adjacency

Adjacent networks

All 59

Every AS seen directly next to AS21700 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS6939Hurricane Electric LLCTransitIPv4 IPv61,973
AS174Cogent Communications, LLCTransitIPv4 IPv61,301
AS3257GTT Communications Inc.TransitIPv4 IPv6795
AS400967Assured NetworksHostingIPv4 IPv6403
AS19949FNFISPUnclassifiedIPv4399
AS53727Penguin NetworksUnclassifiedIPv4 IPv6299
AS401363Lyncross LLCUnclassifiedIPv4 IPv6170
AS63229Nocturnal NetworksUnclassifiedIPv4 IPv6150
AS53343sc NetworkUnclassifiedIPv4 IPv6149
AS961Achieve Wireless IncUnclassifiedIPv4 IPv6131

All 59 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-13 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.22M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.

Inferred from path position, not from any declaration by either party. A network appearing here is carrying these routes; whether that is a paid transit arrangement, a backup, or something else is not something routing data can tell you. Adjacency is not the same as peering. Being next to each other in a path covers paid transit, settlement-free peering and customer connections alike, and routing data cannot distinguish them. Treat this as "these networks exchange routes", nothing more specific.

Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.