asn.dev

Observed topology

AS12257 EMC-AS12257 - Dell, Inc.

Unclassified ARIN

Upstreams 15 carry this network
Downstreams 0 this network carries
Adjacent (IPv4) 15
Adjacent (IPv6) 3
Upstream graph Who carries AS12257, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS12257 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

All 15

Networks observed carrying traffic for AS12257: 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
AS3356Level 3 Parent, LLCTransitIPv4 IPv61,974
AS8220COLT Technology Services Group LimitedHostingIPv4480
AS1273IDDQD-ASBusinessIPv4405
AS7018AT&T Enterprises, LLCResidentialIPv4 IPv6210
AS701Verizon BusinessResidentialIPv4 IPv6199
AS9498BHARTI Airtel Ltd.MobileIPv4132
AS198949Radware LtdUnclassifiedIPv458
AS4657StarHub LtdResidentialIPv457
AS4755TATA Communications formerly VSNL is Leading ISPHostingIPv451
AS5400British Telecommunications LimitedUnclassifiedIPv444

All 15 upstreams →

Transit

Downstream networks

inferred

Networks for which AS12257 was observed as the last hop before the origin, meaning it appears to provide them transit.

No downstream observed. This network does not appear to carry transit for anyone.

Adjacency

Adjacent networks

All 15

Every AS seen directly next to AS12257 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS3356Level 3 Parent, LLCTransitIPv4 IPv61,974
AS8220COLT Technology Services Group LimitedHostingIPv4480
AS1273IDDQD-ASBusinessIPv4405
AS7018AT&T Enterprises, LLCResidentialIPv4 IPv6210
AS701Verizon BusinessResidentialIPv4 IPv6199
AS9498BHARTI Airtel Ltd.MobileIPv4132
AS198949Radware LtdUnclassifiedIPv458
AS4657StarHub LtdResidentialIPv457
AS4755TATA Communications formerly VSNL is Leading ISPHostingIPv451
AS5400British Telecommunications LimitedUnclassifiedIPv444

All 15 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-13 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.40M 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.