asn.dev

Observed topology

AS17621 CNCGROUP-SH China Unicom Shanghai network

Unclassified APNIC

Upstreams 2 carry this network
Downstreams 45 this network carries
Adjacent (IPv4) 44
Adjacent (IPv6) 15
Upstream graph Who carries AS17621, and who carries them, drawn as a map up to the transit-free core. 0 exchanges Where AS17621 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

inferred

Networks observed carrying traffic for AS17621: 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
AS4837CHINA UNICOM China169 BackboneMobileIPv4 IPv629,838
AS9929CHINA UNICOM Industrial Internet BackboneUnclassifiedIPv4 IPv6275

Transit

Downstream networks

All 45

Networks for which AS17621 was observed as the last hop before the origin, meaning it appears to provide them transit.

ASNetworkTypeFamiliesPaths seen
AS37963Hangzhou Alibaba Advertising Co.,Ltd.HostingIPv4 IPv61,991
AS23853Shanghai Data Solution Co., Ltd.UnclassifiedIPv4 IPv6800
AS59083Shanghai Kuanhui Tech. Co.,ltdUnclassifiedIPv4424
AS9809SHENZHEN NOVA TECHNOLOGIES DEVELOPMENT.,LTD.UnclassifiedIPv4378
AS146842ChinaDataCom Corporation LimitedUnclassifiedIPv4284
AS45079GDS CHANGAN SERVICES Ltd.UnclassifiedIPv4 IPv6203
AS10212China Enterprise ICT Solutions LimitedUnclassifiedIPv4176
AS17775shanghai science and technology network communication limited companyUnclassifiedIPv4132
AS24141Shanghai DMT Information Network cor.,LTD.UnclassifiedIPv4126
AS37965Pacnet Business Solutions LTDUnclassifiedIPv4123

All 45 downstreams →

Adjacency

Adjacent networks

All 47

Every AS seen directly next to AS17621 in a routing path, in either direction.

ASNetworkTypeFamiliesPaths seen
AS4837CHINA UNICOM China169 BackboneMobileIPv4 IPv635,096
AS37963Hangzhou Alibaba Advertising Co.,Ltd.HostingIPv4 IPv61,991
AS23853Shanghai Data Solution Co., Ltd.UnclassifiedIPv4 IPv6800
AS9929CHINA UNICOM Industrial Internet BackboneUnclassifiedIPv4 IPv6559
AS59083Shanghai Kuanhui Tech. Co.,ltdUnclassifiedIPv4424
AS9809SHENZHEN NOVA TECHNOLOGIES DEVELOPMENT.,LTD.UnclassifiedIPv4378
AS146842ChinaDataCom Corporation LimitedUnclassifiedIPv4284
AS45079GDS CHANGAN SERVICES Ltd.UnclassifiedIPv4 IPv6203
AS10212China Enterprise ICT Solutions LimitedUnclassifiedIPv4176
AS17775shanghai science and technology network communication limited companyUnclassifiedIPv4132

All 47 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-10-15 10:00 UTC by route-views2,rrc00, as seen from 75 BGP vantage points across 73.09M 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.