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Autonomous System

AS17621 · China Unicom Shanghai network

Overview

AS17621 is announced on the Internet: RIPE RIS route collectors currently see 388 IPv4 prefixes and 425 IPv6 prefixes originated by this network. Together, its IPv4 prefixes cover 1,022,720 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 2 upstream neighbours (transit providers or peers) and 48 downstream neighbours (customers or networks it carries). Its most visible upstreams are CHINA UNICOM China169 Backbone (AS4837) and CHINA UNICOM Industrial Internet Backbone (AS9929). AS17621 was assigned by APNIC, and its registration country is China.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 17, 2026 at 7:01 AM UTC. This page is refreshed at most every 12 hours.

Go further

The trace goes to 58.246.0.1, the first address of 58.246.0.0/16. An address picked inside a prefix may not answer (nothing listens there, or the network filters probes): the trace then shows the path up to the last network that replies.

Announced prefixes

IPv4 prefixes (388 prefixes)

PrefixAddresses
27.115.0.0/1732,768
27.115.0.0/1816,384
27.115.118.0/23512
27.115.120.0/221,024
27.115.122.0/24256
27.115.123.0/24256
27.115.124.0/23512
27.115.124.0/24256
27.115.126.0/23512
43.243.148.0/221,024
43.243.148.0/23512
43.243.149.0/24256
43.243.150.0/23512
43.243.150.0/24256
43.243.151.0/24256
43.250.144.0/221,024
43.250.146.0/24256
43.250.147.0/24256
43.254.224.0/221,024
58.246.0.0/1665,536
58.246.95.0/24256
58.247.0.0/1665,536
58.247.22.0/24256
58.247.108.0/24256
58.247.244.0/24256
58.247.245.0/24256
58.247.247.0/24256
59.81.64.0/23512
59.81.106.0/23512
101.52.212.0/221,024
101.52.216.0/221,024
101.52.220.0/221,024
101.52.248.0/221,024
101.52.252.0/221,024
103.5.192.0/23512
103.5.194.0/24256
103.24.116.0/24256
103.24.118.0/23512
103.36.136.0/24256
103.36.137.0/24256
103.36.138.0/24256
103.36.139.0/24256
103.36.168.0/24256
103.36.172.0/24256
103.36.173.0/24256
103.38.232.0/221,024
103.38.232.0/23512
103.38.234.0/23512
103.38.235.0/24256
103.45.169.0/24256
103.61.190.0/24256
103.108.244.0/24256
103.111.64.0/24256
103.140.14.0/23512
103.144.159.0/24256
103.147.124.0/24256
103.164.32.0/24256
103.200.220.0/24256
103.200.222.0/24256
103.200.223.0/24256
103.200.224.0/24256
103.200.232.0/24256
103.202.92.0/221,024
103.202.96.0/221,024
103.202.100.0/221,024
103.202.104.0/221,024
103.202.108.0/221,024
103.202.112.0/221,024
103.202.120.0/221,024
103.202.124.0/221,024
103.202.128.0/221,024
103.202.132.0/221,024
103.202.136.0/221,024
103.202.140.0/221,024
103.202.144.0/221,024
103.231.16.0/24256
103.234.128.0/24256
103.234.129.0/24256
103.234.131.0/24256
103.238.184.0/24256
103.250.192.0/221,024
103.250.192.0/24256
103.250.193.0/24256
106.75.208.0/204,096
106.75.224.0/204,096
106.75.240.0/204,096
110.43.128.0/212,048
110.43.136.0/212,048
110.43.144.0/212,048
110.43.152.0/212,048
112.64.0.0/1665,536
112.64.0.0/1732,768
112.64.114.0/24256
112.64.128.0/1732,768
112.64.199.0/24256
112.64.200.0/24256
112.64.212.0/24256
112.64.213.0/24256
112.64.214.0/24256
112.64.238.0/24256

Showing the first 100 of 388, in address order. Complete list on RIPEstat

IPv6 prefixes (425 prefixes)

Prefix
2403:a100::/48
2403:a200:a1ff::/48
2404:7600:101::/48
2405:1480:1000::/48
2405:7040:6001::/48
2408:8000:9000::/36
2408:8000:91f0::/44
2408:8024:8000::/33
2408:8025::/32
2408:8026::/32
2408:8026:3e0::/44
2408:8026:3f0::/44
2408:8026:4e0::/44
2408:8026:510::/44
2408:8026:520::/44
2408:8026:700::/44
2408:8026:8f0::/44
2408:8026:900::/44
2408:80f1:10::/44
2408:80f1:50::/44
2408:80f1:80::/44
2408:80f1:90::/44
2408:80f1:a0::/44
2408:80f1:b0::/44
2408:80f1:c0::/44
2408:80f1:d0::/44
2408:80f1:e0::/44
2408:80f1:f0::/44
2408:80f1:100::/44
2408:80f1:180::/44
2408:80f1:190::/44
2408:80f1:1b0::/44
2408:80f1:200::/40
2408:80f1:230::/44
2408:820c::/32
2408:820c::/44
2408:820c:10::/44
2408:820c:20::/44
2408:820c:30::/44
2408:820c:40::/44
2408:820c:50::/44
2408:820c:60::/44
2408:820c:d00::/44
2408:820c:d10::/44
2408:820c:d20::/44
2408:820c:d40::/44
2408:820c:1a00::/44
2408:820c:1a10::/44
2408:820c:1a20::/44
2408:820c:1a30::/44
2408:820c:1a40::/44
2408:820c:1a50::/44
2408:820c:2700::/44
2408:820c:2710::/44
2408:820c:2720::/44
2408:820c:2730::/44
2408:820c:2740::/44
2408:820c:3410::/44
2408:820c:3420::/44
2408:820c:3430::/44
2408:820c:3440::/44
2408:820c:4e00::/44
2408:820c:4e10::/44
2408:820c:5b10::/44
2408:820c:5b20::/44
2408:820c:5b30::/44
2408:820c:5b40::/44
2408:820c:6800::/44
2408:820c:6810::/44
2408:820c:6840::/44
2408:820c:6850::/44
2408:820c:6870::/44
2408:820c:6880::/44
2408:820c:6890::/44
2408:820c:7500::/44
2408:820c:7510::/44
2408:820c:7520::/44
2408:820c:7530::/44
2408:820c:7540::/45
2408:820c:7548::/45
2408:820c:7550::/45
2408:820c:7558::/45
2408:820c:7560::/44
2408:820c:8200::/44
2408:820c:8210::/44
2408:820c:8220::/44
2408:820c:8230::/44
2408:820c:8240::/44
2408:820c:8260::/44
2408:820c:8f00::/44
2408:820c:8f10::/44
2408:820c:8f20::/44
2408:820c:8f30::/44
2408:820c:8f40::/44
2408:820c:8f50::/44
2408:820c:8f60::/44
2408:820c:8f70::/44
2408:820c:8f80::/44
2408:820c:8f90::/44
2408:820c:8fa0::/44

Showing the first 100 of 425, in address order. Complete list on RIPEstat

Neighbours

Upstreams (transit or peers) (2)

ASNetworkVisibility
AS4837CHINA UNICOM China169 Backbone5,765
AS9929CHINA UNICOM Industrial Internet Backbone527

Downstreams (customers) (48)

ASNetworkVisibility
AS37963Hangzhou Alibaba Advertising Co.,Ltd.536
AS10212China Enterprise ICT Solutions Limited526
AS45079GDS CHANGAN SERVICES Ltd.315
AS59083KHTech - Shanghai Kuanhui Tech. Co.,ltd305
AS10100UBS Group AG289
AS109CISCO SYSTEMS, INC.276
AS63570China Internet Network Information Center275
AS9809NovaNetwork - SHENZHEN NOVA TECHNOLOGIES DEVELOPMENT.,LTD.266
AS24141Shanghai DMT Information Network cor.,LTD.262
AS137759MTS SYSTEM (China) Co.,Ltd255
AS58850-239
AS7609-238
AS56006-133
AS146842-133
AS139148China UnionPay Co., Ltd129
AS23853-122
AS139138-87
AS56013-81
AS151247-77
AS137758-71
AS137746-70
AS38375-67
AS38381-59
AS17739-54
AS135432-51
AS17775-41
AS37965-40
AS59019-37
AS139184-30
AS55992-25

The 30 most visible of 48.

Visibility is RIPEstat's count of how often the route collectors observed the link. It compares neighbours with each other; it is not a traffic volume.

How to read this page

An Autonomous System (AS) is a network run under one routing policy: an internet provider, a cloud, a content network, a university. Each one has a number, its ASN, assigned by a regional registry (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC), and uses BGP, the protocol networks use to tell each other where addresses are, to announce the blocks of addresses it delivers to.

A prefix such as 203.0.113.0/24 is a block of addresses: the number after the slash says how many bits are fixed, so a /24 holds 256 IPv4 addresses and a /16 holds 65,536. Networks often announce a large block and smaller pieces of it at the same time, which is why the address total counts each address once.

Neighbours come from the paths themselves. A network that appears just before this one in a path, on the collector's side, is an upstream: a transit provider or a peer. One that appears just after it is a downstream, usually a customer. Peering at an internet exchange also shows up as an upstream, so the upstream list is not a list of paid transit.

The data comes from RIPEstat, run by the RIPE NCC, which gathers the routing tables of hundreds of networks through its RIS route collectors. This page reads it when it is visited and keeps it for 12 hours at most; the BGP viewer reads it live.

Frequently asked questions

How do I find the ASN of an IP address?
Type the address in the BGP viewer: it shows the prefix that covers it, the AS that originates that prefix and the paths seen towards it. A traceroute also names the network of each hop, so you can see every AS a connection crosses.
Why does one company have several ASNs?
Large operators split their network by region, by activity or by history: a cloud may use one number for its backbone and another for a region, and every acquisition brings its own numbers. Each number has its own page, with its own prefixes and neighbours.
Why do prefix counts differ from one site to another?
Each source sees the routing table from different collectors, at a different time, and counts differently: some include prefixes withdrawn in recent weeks, some merge a block and its pieces. This page counts the prefixes RIPE RIS collectors see originated by the network at the end of the latest two-week window, and counts each IPv4 address once.
Is this the list of IP ranges of a cloud provider?
It is what its networks announce, which is what the Internet routes to them. Many providers also publish an official list of ranges per service and region; that list is the reference for firewall rules, because a range can be announced before it is used, or announced by another of their AS numbers.