asn.dev

Observed topology

AS12271 TWC-12271-NYC

Upstreams 2 carry this network
Downstreams 47 this network carries
Adjacent (IPv4) 48
Adjacent (IPv6) 7

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS12271: 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
AS7843Charter Communications IncResidentialIPv4 IPv67,001
AS6453TATA COMMUNICATIONS (AMERICA) INCTransitIPv421

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.

Transit

Downstream networks

inferred

Networks for which AS12271 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS31869LL BeanUnclassifiedIPv4366
AS22252The City of New YorkUnclassifiedIPv4275
AS36100MTC Broadband, Inc.UnclassifiedIPv4240
AS18564St. John's University, New YorkUnclassifiedIPv4237
AS19796Shubert Organization, Inc.UnclassifiedIPv4187
AS393753The Brooklyn Hospital CenterUnclassifiedIPv4183
AS54226SUNY College of OptometryUnclassifiedIPv4183
AS395095Orange Regional Medical CenterUnclassifiedIPv4126
AS18694Sappi Fine Paper North AmericaUnclassifiedIPv4116
AS54113Fastly, Inc.HostingIPv4 IPv698
AS14478Recurse CenterUnclassifiedIPv4 IPv698
AS22303State University of New York at New PaltzUnclassifiedIPv4 IPv674
AS20252Joan and Sanford I. Weill Medical College and Graduate School of Medical Sciences of Cornell UniversityUnclassifiedIPv471
AS46765Liberum Capital Inc.UnclassifiedIPv463
AS27185Danbury Hospital - ITGUnclassifiedIPv463
AS55123Brilliant Jewelers/MJJ Inc.UnclassifiedIPv463
AS401827UNFCUUnclassifiedIPv463
AS32730LG CNS America Inc.UnclassifiedIPv463
AS402494BartlettUnclassifiedIPv463
AS16770Astoria Generating Company, L.P.UnclassifiedIPv463
AS402355VisentryUnclassifiedIPv463
AS23325Magnitude Capital, LLCUnclassifiedIPv461
AS14465HITNUnclassifiedIPv461
AS395060Macmillan Publishers IncUnclassifiedIPv460
AS19794The Cementworks LLCUnclassifiedIPv459
AS6292MTAPDUnclassifiedIPv4 IPv643
AS397595MTAPDUnclassifiedIPv4 IPv643
AS40170Intermetro Communications, Inc.UnclassifiedIPv437
AS3935699/11 MEMORIALUnclassifiedIPv436
AS62566Starbucks Coffee CompanyUnclassifiedIPv436
AS33010The Interchurch CenterUnclassifiedIPv435
AS397352Medisys Health Network, Inc.UnclassifiedIPv435
AS393562Mobilitie, LLCUnclassifiedIPv635
AS33428The New-York Historical SocietyUnclassifiedIPv433
AS26738Deerfield Partners, L.P.UnclassifiedIPv433
AS25891School Of Visual Arts, Inc.UnclassifiedIPv433
AS14460Horizon Media, Inc.UnclassifiedIPv431
AS400392Empire Resorts, Inc.UnclassifiedIPv431
AS53693Ralph Appelbaum Associates, Inc.UnclassifiedIPv431
AS25816Touro CollegeUnclassifiedIPv430
AS25669MARKERTEK VIDEO SUPPLYUnclassifiedIPv428
AS30012Universal Music Group, INC.UnclassifiedIPv426
AS395359InTouch HealthUnclassifiedIPv426
AS5091Stripe, Inc.UnclassifiedIPv424
AS40362Chapin SchoolUnclassifiedIPv422
AS23097COHEN & STEERS CAPITAL MGMT., INC.UnclassifiedIPv420
AS30339Davis & Gilbert LLPUnclassifiedIPv47

Adjacency

Adjacent networks

55 shown

Every AS seen directly next to AS12271 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS7843Charter Communications IncResidentialIPv4 IPv610,675
AS31869LL BeanUnclassifiedIPv4366
AS22252The City of New YorkUnclassifiedIPv4275
AS36100MTC Broadband, Inc.UnclassifiedIPv4240
AS18564St. John's University, New YorkUnclassifiedIPv4237
AS19796Shubert Organization, Inc.UnclassifiedIPv4187
AS54226SUNY College of OptometryUnclassifiedIPv4183
AS393753The Brooklyn Hospital CenterUnclassifiedIPv4183
AS395095Orange Regional Medical CenterUnclassifiedIPv4126
AS18694Sappi Fine Paper North AmericaUnclassifiedIPv4116
AS14478Recurse CenterUnclassifiedIPv4 IPv698
AS54113Fastly, Inc.HostingIPv4 IPv698
AS22303State University of New York at New PaltzUnclassifiedIPv4 IPv674
AS20252Joan and Sanford I. Weill Medical College and Graduate School of Medical Sciences of Cornell UniversityUnclassifiedIPv471
AS402355VisentryUnclassifiedIPv463
AS55123Brilliant Jewelers/MJJ Inc.UnclassifiedIPv463
AS401827UNFCUUnclassifiedIPv463
AS27185Danbury Hospital - ITGUnclassifiedIPv463
AS16770Astoria Generating Company, L.P.UnclassifiedIPv463
AS46765Liberum Capital Inc.UnclassifiedIPv463
AS402494BartlettUnclassifiedIPv463
AS32730LG CNS America Inc.UnclassifiedIPv463
AS14465HITNUnclassifiedIPv461
AS23325Magnitude Capital, LLCUnclassifiedIPv461
AS395060Macmillan Publishers IncUnclassifiedIPv460
AS19794The Cementworks LLCUnclassifiedIPv459
AS6292MTAPDUnclassifiedIPv4 IPv643
AS397595MTAPDUnclassifiedIPv4 IPv643
AS40170Intermetro Communications, Inc.UnclassifiedIPv437
AS3935699/11 MEMORIALUnclassifiedIPv436
AS62566Starbucks Coffee CompanyUnclassifiedIPv436
AS393562Mobilitie, LLCUnclassifiedIPv635
AS397352Medisys Health Network, Inc.UnclassifiedIPv435
AS33010The Interchurch CenterUnclassifiedIPv435
AS26738Deerfield Partners, L.P.UnclassifiedIPv433
AS25891School Of Visual Arts, Inc.UnclassifiedIPv433
AS33428The New-York Historical SocietyUnclassifiedIPv433
AS400392Empire Resorts, Inc.UnclassifiedIPv431
AS14460Horizon Media, Inc.UnclassifiedIPv431
AS53693Ralph Appelbaum Associates, Inc.UnclassifiedIPv431
AS25816Touro CollegeUnclassifiedIPv430
AS25669MARKERTEK VIDEO SUPPLYUnclassifiedIPv428
AS395359InTouch HealthUnclassifiedIPv426
AS30012Universal Music Group, INC.UnclassifiedIPv426
AS5091Stripe, Inc.UnclassifiedIPv424
AS40362Chapin SchoolUnclassifiedIPv422
AS6453TATA COMMUNICATIONS (AMERICA) INCTransitIPv421
AS23097COHEN & STEERS CAPITAL MGMT., INC.UnclassifiedIPv420
AS30339Davis & Gilbert LLPUnclassifiedIPv47

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.

Interconnection

Exchange presence

recorded

Internet exchanges where Packet Clearing House has a port recorded for AS12271, largest fabric first. An exchange is shared switching where networks interconnect directly rather than paying a transit provider to carry traffic between them, so turning up at one is a deliberate choice about how this network wants to be reached. Each name opens that exchange's own page, with its peering LANs and every other network recorded on it.

No exchange membership on file. That is not the same as peering nowhere: the dataset records what PCH has collected, and many exchanges publish no participant list at all.

Unlike the tables above, this is recorded rather than inferred. An address on a peering LAN is at that exchange by definition. Two carve-outs all the same. Member ports counts every participant at the exchange, not this network's ports, so read it as a size proxy. And an absent exchange means PCH has no record of it, not that the network is not there.

Provenance

Where this comes from

Derived from routing tables collected at 2026-08-08 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 74.02M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.

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

Exchange presence comes from a separate dataset: the directory collected 2026-08-09 by Packet Clearing House (https://www.pch.net/ixp/data), covering 1,327 exchanges and 93,164 recorded member ports, licensed CC BY-NC-SA 3.0.

PeeringDB is the better-known directory and is deliberately not the source here: its acceptable-use policy forbids the bulk storage this needs. The two answer different questions anyway. PeeringDB reports what an operator declares about itself; this reports what PCH has recorded.