asn.dev

Observed topology

AS2721 SCLR - CULR, LLC

Unclassified ARIN

Upstreams 5 carry this network
Downstreams 4 this network carries
Adjacent (IPv4) 9
Adjacent (IPv6) 2
Upstream graph Who carries AS2721, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS2721 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS2721: 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, LLCTransitIPv4121
AS11164Internet2EducationIPv4 IPv670
AS11537Internet2UnclassifiedIPv428
AS2711Spirit CommunicationsUnclassifiedIPv417
AS3257GTT Communications Inc.TransitIPv42

Transit

Downstream networks

inferred

Networks for which AS2721 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS13429Medical University of South CarolinaUnclassifiedIPv4315
AS2722CULR, LLCUnclassifiedIPv4 IPv6188
AS12005University of South CarolinaUnclassifiedIPv417
AS13548College of CharlestonUnclassifiedIPv412

Adjacency

Adjacent networks

observed

Every AS seen directly next to AS2721 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS174Cogent Communications, LLCTransitIPv4484
AS2722CULR, LLCUnclassifiedIPv4 IPv6432
AS13429Medical University of South CarolinaUnclassifiedIPv4315
AS11164Internet2EducationIPv4 IPv6240
AS11537Internet2UnclassifiedIPv4118
AS2711Spirit CommunicationsUnclassifiedIPv460
AS3257GTT Communications Inc.TransitIPv442
AS12005University of South CarolinaUnclassifiedIPv417
AS13548College of CharlestonUnclassifiedIPv412

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-03 10:00 UTC by route-views2,rrc00, as seen from 76 BGP vantage points across 74.45M 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.