Observed topology

AS21528 ALASCONNECT

Unclassified ARIN

Upstreams 3 carry this network

Downstreams 1 this network carries

Adjacent (IPv4) 4

Adjacent (IPv6) 1

Upstream graph Who carries AS21528, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS21528 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS21528: 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.

AS	Network	Type	Families	Paths seen
AS11090	Matanuska Telecom Association, Incorporated	Residential	IPv4 IPv6	235
AS7782	Alaska Communications Systems Group, Inc.	Residential	IPv4	56
AS8047	GENERAL COMMUNICATION, INC.	Residential	IPv4	10

Transit

Downstream networks

inferred

Networks for which AS21528 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS18443	Alyeska Pipeline Service Company	Unclassified	IPv4	63

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS21528 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS11090	Matanuska Telecom Association, Incorporated	Residential	IPv4 IPv6	298
AS18443	Alyeska Pipeline Service Company	Unclassified	IPv4	63
AS7782	Alaska Communications Systems Group, Inc.	Residential	IPv4	56
AS8047	GENERAL COMMUNICATION, INC.	Residential	IPv4	10

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-30 10:00 UTC by route-views2,rrc00, as seen from 76 BGP vantage points across 74.49M 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.