asn.dev

Observed topology

AS21859 ZEN-ECN - Zenlayer Inc

Hosting DROP-listed space ARIN

Upstreams 128 carry this network
Downstreams 234 this network carries
Adjacent (IPv4) 361
Adjacent (IPv6) 147
Upstream graph Who carries AS21859, and who carries them, drawn as a map up to the transit-free core. 65 exchanges Where AS21859 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

All 128

Networks observed carrying traffic for AS21859: 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
AS4229Zenlayer IncHostingIPv4 IPv641,427
AS1299Arelion Sweden ABTransitIPv4 IPv67,702
AS6939Hurricane Electric LLCTransitIPv4 IPv65,564
AS2914NTT America, Inc.TransitIPv4 IPv65,323
AS174Cogent Communications, LLCTransitIPv4 IPv63,539
AS3356Level 3 Parent, LLCTransitIPv4 IPv63,533
AS38082True International Gateway Co., Ltd.UnclassifiedIPv4 IPv62,217
AS3257GTT Communications Inc.TransitIPv4 IPv62,166
AS9498BHARTI Airtel Ltd.MobileIPv4 IPv62,053
AS6461Zayo BandwidthTransitIPv4 IPv61,903

All 128 upstreams →

Transit

Downstream networks

All 234

Networks for which AS21859 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS62610Zenlayer IncUnclassifiedIPv4 IPv615,334
AS135377UCLOUD INFORMATION TECHNOLOGY (HK) LIMITEDUnclassifiedIPv4 IPv69,924
AS24429Zhejiang Taobao Network Co.,LtdHostingIPv4 IPv67,730
AS5065Bunny CommunicationsUnclassifiedIPv47,591
AS152179GLOBAL COMMUNICATION NETWORK LIMITEDResidentialIPv47,375
AS26658HTHostingIPv45,513
AS139341ACEHostingIPv4 IPv65,035
AS401783TOKALA COMMUNICATIONS INC.UnclassifiedIPv44,406
AS214143SKYDIGITAL TELECOM LTDUnclassifiedIPv44,024
AS45102Alibaba (US) Technology Co., Ltd.HostingIPv4 IPv63,401

All 234 downstreams →

Adjacency

Adjacent networks

All 361

Every AS seen directly next to AS21859 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS4229Zenlayer IncHostingIPv4 IPv6146,724
AS62610Zenlayer IncUnclassifiedIPv4 IPv648,245
AS135377UCLOUD INFORMATION TECHNOLOGY (HK) LIMITEDUnclassifiedIPv4 IPv640,061
AS1299Arelion Sweden ABTransitIPv4 IPv625,664
AS2914NTT America, Inc.TransitIPv4 IPv617,268
AS6939Hurricane Electric LLCTransitIPv4 IPv613,785
AS3356Level 3 Parent, LLCTransitIPv4 IPv610,909
AS174Cogent Communications, LLCTransitIPv4 IPv68,726
AS3257GTT Communications Inc.TransitIPv4 IPv68,112
AS152179GLOBAL COMMUNICATION NETWORK LIMITEDResidentialIPv47,855

All 361 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-11 10:00 UTC by route-views2,rrc00, as seen from 74 BGP vantage points across 73.24M 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.