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AS17621China Unicom Shanghai network

ChinaRegistryAPNICTypeCarrier

As of 27th September 2026, AS17621 (China Unicom Shanghai network), a transit carrier registered in China with APNIC, originates 388 IPv4 prefixes covering 1.3M addresses and 424 IPv6 prefixes. By IPv4 address space that makes it the 387th-largest of the 79,525 networks we see originating IPv4, and the 30th-largest of 607 in China. It is seen behind 2 upstream networks, most often AS4837 (China Unicom Backbone) and AS9929 (China Unicom Industrial Internet…), and in front of 36 downstream networks. 98% of its announcements have a valid RPKI ROA; 4 are RPKI-invalid. 85% of its routes reach at least 90% of full-feed peers, and 122 prefixes are also originated by another network.

At a glance

IPv4 prefixes

388

IPv6 prefixes

424

IPv4 addresses

1.3M

IPv6 /64s

107B

Upstream graph

The networks AS17621 is seen behind, one and two hops out, drawn from real AS paths.

AS17621Toward the internet core
Upstream graph for AS17621: 5 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS17621China Unicom Shan…This networkAS4837China Unicom Back…AS9929China Unicom Indu…AS174Cogent Communicat…AS1299Arelion (fka. Tel…AS10099China Unicom Glob…

Networks observed one and two hops upstream of AS17621 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.

Neighbouring networks

88

adjacent networks

Upstreams
22%
Peers
5057%
Downstreams
3641%

Networks carrying this one's traffic toward the rest of the internet.

Upstreams of AS17621
NetworkCountryRelationshipPathsVantage pts
AS4837China Unicom BackboneCNPeer53,846144
AS9929China Unicom Industrial Internet BackboneCNPeer793143

Prefixes

All 812

The largest blocks AS17621 originates, widest first.

Largest prefixes originated by AS17621
PrefixAddressesVisibility
58.246.0.0/1665.5k81/81
58.247.0.0/1665.5k81/81
112.64.0.0/1665.5k81/81
112.65.0.0/1665.5k81/81
139.226.0.0/1665.5k81/81
139.227.0.0/1665.5k81/81
140.206.0.0/1665.5k81/81
140.207.0.0/1665.5k81/81
223.166.0.0/1665.5k81/81
223.167.0.0/1665.5k81/81

Routing health

How AS17621's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.

RPKI origin validation

  • Valid98.2%797
  • Invalid0.5%4
  • No ROA1.4%11

Propagation

  • Globally propagated90% of full-feed peers or more84.6%687
  • Partially propagated40% to 90%0.4%3
  • Seen by few peersUnder 40%15.0%122

Prefix sizes

IPv4 — 388 prefixes

IPv6 — 424 prefixes

  • /324.3B × /645.4%23
  • /332.1B × /640.7%3
  • /36268M × /640.2%1
  • /4016.8M × /648.7%37
  • /424.2M × /644.0%17
  • /432.1M × /6440.1%170
  • /441M × /6433.7%143
  • /45524k × /641.4%6
  • /46262k × /640.2%1
  • /4865.5k × /645.4%23

Recent changes

Announcements that started or stopped since 28th Aug 2026.

Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.