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Autonomous System

AS21859 · Zenlayer Inc

Overview

AS21859 is announced on the Internet: RIPE RIS route collectors currently see 1,722 IPv4 prefixes and 167 IPv6 prefixes originated by this network. Together, its IPv4 prefixes cover 723,712 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 205 upstream neighbours (transit providers or peers) and 233 downstream neighbours (customers or networks it carries). Its most visible upstreams are Zenlayer Inc (AS4229), Arelion Sweden AB (AS1299), and NTT America, Inc. (AS2914). AS21859 was assigned by ARIN, and its registration country is United States.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 17, 2026 at 12:57 AM UTC. This page is refreshed at most every 12 hours.

Go further

Trace a route to this networkOpen in the BGP viewerWHOIS of 128.1.0.1

The trace goes to 128.1.0.1, the first address of 128.1.0.0/16. 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 (1,722 prefixes)

PrefixAddresses
2.27.161.0/24256
5.252.82.0/24256
8.23.192.0/23512
14.102.227.0/24256
23.27.112.0/24256
23.90.128.0/204,096
23.90.144.0/204,096
23.90.160.0/212,048
23.90.168.0/221,024
23.90.168.0/23512
23.90.170.0/23512
23.90.172.0/23512
23.90.174.0/23512
23.90.176.0/221,024
23.90.180.0/221,024
23.90.180.0/24256
23.90.181.0/24256
23.90.182.0/24256
23.90.183.0/24256
23.90.184.0/23512
23.90.186.0/23512
23.90.188.0/221,024
23.91.102.0/23512
23.91.108.0/24256
23.139.252.0/24256
23.154.4.0/24256
23.154.44.0/24256
23.154.76.0/24256
23.154.84.0/24256
23.154.92.0/24256
23.154.108.0/24256
23.154.140.0/24256
23.154.148.0/24256
23.236.65.0/24256
23.236.70.0/24256
23.236.96.0/24256
23.236.97.0/24256
23.236.98.0/24256
23.236.99.0/24256
23.236.100.0/23512
23.236.101.0/24256
23.236.102.0/23512
23.236.103.0/24256
23.236.104.0/23512
23.236.104.0/24256
23.236.106.0/24256
23.236.107.0/24256
23.236.108.0/24256
23.236.109.0/24256
23.236.110.0/24256
23.236.112.0/204,096
23.236.112.0/23512
23.236.114.0/24256
23.236.116.0/24256
23.236.118.0/24256
23.236.119.0/24256
23.236.120.0/221,024
23.236.123.0/24256
23.236.124.0/24256
23.236.125.0/24256
23.236.127.0/24256
23.248.160.0/198,192
23.248.160.0/24256
23.248.161.0/24256
23.248.164.0/24256
23.248.165.0/24256
23.248.166.0/23512
23.248.168.0/221,024
23.248.172.0/24256
23.248.173.0/24256
23.248.176.0/23512
23.248.178.0/24256
23.248.179.0/24256
23.248.180.0/24256
23.248.181.0/24256
23.248.182.0/24256
23.248.183.0/24256
23.248.186.0/23512
23.248.189.0/24256
23.248.190.0/23512
23.251.96.0/198,192
23.251.96.0/24256
23.251.97.0/24256
23.251.98.0/23512
23.251.100.0/23512
23.251.102.0/24256
23.251.103.0/24256
23.251.106.0/23512
23.251.108.0/221,024
23.251.112.0/24256
23.251.113.0/24256
23.251.114.0/24256
23.251.115.0/24256
23.251.116.0/23512
23.251.118.0/23512
23.251.120.0/24256
23.251.121.0/24256
23.251.122.0/24256
23.251.123.0/24256
23.251.124.0/221,024

Showing the first 100 of 1,722, in address order. Complete list on RIPEstat

IPv6 prefixes (167 prefixes)

Prefix
2403:8300:e00::/48
2403:8300:e02::/48
2403:8300:e04::/47
2403:8300:e08::/46
2404:3700::/48
2404:ff40:2000::/36
2404:ff40:3000::/36
240d:c010:14b::/48
240d:c010:14c::/48
2602:fed2:731a::/48
2602:ffe4::/38
2602:ffe4:3::/48
2602:ffe4:400::/38
2602:ffe4:401::/48
2602:ffe4:800::/38
2602:ffe4:c01::/48
2602:ffe4:c02::/48
2602:ffe4:c03::/48
2602:ffe4:c05::/48
2602:ffe4:c06::/48
2602:ffe4:c07::/48
2602:ffe4:c09::/48
2602:ffe4:c0a::/48
2602:ffe4:c0b::/48
2602:ffe4:c0d::/48
2602:ffe4:c11::/48
2602:ffe4:c13::/48
2602:ffe4:c14::/48
2602:ffe4:c15::/48
2602:ffe4:c16::/48
2602:ffe4:c18::/48
2602:ffe4:c19::/48
2602:ffe4:c1a::/48
2602:ffe4:c1c::/48
2602:ffe4:c1f::/48
2602:ffe4:c20::/48
2602:ffe4:c21::/48
2602:ffe4:c22::/48
2602:ffe4:c26::/48
2602:ffe4:c27::/48
2602:ffe4:c34::/48
2602:ffe4:c37::/48
2602:ffe4:c3b::/48
2602:ffe4:c3c::/48
2602:ffe4:c3e::/48
2602:ffe4:c40::/48
2602:ffe4:c41::/48
2602:ffe4:c42::/48
2602:ffe4:c44::/48
2602:ffe4:c45::/48
2602:ffe4:c48::/48
2602:ffe4:c49::/48
2602:ffe4:c4a::/48
2602:ffe4:c4b::/48
2602:ffe4:c4c::/48
2602:ffe4:c4d::/48
2602:ffe4:c4e::/48
2602:ffe4:c4f::/48
2602:ffe4:c50::/48
2602:ffe4:c51::/48
2602:ffe4:c52::/48
2602:ffe4:c53::/48
2602:ffe4:c54::/48
2602:ffe4:c56::/48
2602:ffe4:c57::/48
2602:ffe4:c58::/48
2602:ffe4:c5b::/48
2602:ffe4:c5d::/48
2602:ffe4:c5e::/48
2602:ffe4:c64::/48
2602:ffe4:c65::/48
2602:ffe4:c6c::/48
2602:ffe4:c6d::/48
2602:ffe4:c6e::/48
2602:ffe4:c70::/48
2602:ffe4:c72::/48
2602:ffe4:c79::/48
2602:ffe4:c7a::/48
2602:ffe4:c7b::/48
2602:ffe4:c9c::/48
2602:ffe4:c9d::/48
2602:ffe4:c9e::/48
2602:ffe4:ca0::/48
2602:ffe4:ca3::/48
2604:980:1000::/36
2604:980:2000::/36
2604:980:3000::/36
2604:980:3008::/48
2604:980:4000::/36
2604:980:5000::/36
2604:980:7000::/36
2604:980:7003::/48
2604:980:7005::/48
2604:980:8000::/36
2604:980:9000::/36
2604:980:a000::/36
2604:980:b000::/36
2604:980:d000::/36
2604:980:e000::/48
2604:980:e001::/48

Showing the first 100 of 167, in address order. Complete list on RIPEstat

Neighbours

Upstreams (transit or peers) (205)

ASNetworkVisibility
AS4229Zenlayer Inc60,276
AS1299Arelion Sweden AB10,288
AS2914NTT America, Inc.9,597
AS20764CJSC RASCOM6,698
AS6939Hurricane Electric LLC6,392
AS38082True International Gateway Co., Ltd.6,034
AS4788TM TECHNOLOGY SERVICES SDN. BHD.5,959
AS174Cogent Communications, LLC5,086
AS6762TELECOM ITALIA SPARKLE S.p.A.5,034
AS9299Philippine Long Distance Telephone Company4,635
AS3257GTT Communications Inc.4,251
AS8529-3,683
AS7195EDGEUNO S.A.S3,441
AS18403-3,185
AS12389PJSC Rostelecom2,892
AS3356Level 3 Parent, LLC2,731
AS3462Data Communication Business Group2,395
AS9498BHARTI Airtel Ltd.2,349
AS40850-2,307
AS12956TELEFONICA GLOBAL SOLUTIONS SL2,233
AS198803Alonstelefonstroy LLP2,127
AS8966EMIRATES TELECOMMUNICATIONS GROUP COMPANY (ETISALAT GROUP) PJSC2,122
AS6461Zayo Bandwidth2,020
AS39386-1,934
AS200612GulfBridgeInternational Gulf Bridge International Inc.1,927
AS29752-1,910
AS4775Globe Telecoms1,466
AS9260Multinet Pakistan Pvt. Ltd.1,433
AS1221Telstra Limited1,386
AS12365-1,078

The 30 most visible of 205.

Downstreams (customers) (233)

ASNetworkVisibility
AS62610Zenlayer Inc25,737
AS135377UCLOUD INFORMATION TECHNOLOGY (HK) LIMITED20,084
AS24429Taobao - Zhejiang Taobao Network Co.,Ltd7,618
AS139341ACE4,963
AS142002Scloud Pte Ltd3,961
AS139057Edgenext Legend Dynasty Pte. Ltd.3,858
AS5065Bunny Communications3,330
AS17497Liasail Global Hongkong Limited3,212
AS152179GLOBAL COMMUNICATION NETWORK LIMITED2,858
AS396986Bytedance Inc.2,508
AS7346-2,119
AS151373-2,027
AS45903CMC Telecom Infrastructure Company1,912
AS150436-1,909
AS13444-1,877
AS38854-1,747
AS400866-1,665
AS63473HostHatch, LLC1,640
AS136744-1,637
AS52129-1,623
AS151397-1,505
AS395793-1,371
AS401783-1,326
AS393437-1,314
AS29752-1,292
AS137280-1,291
AS18464-1,281
AS45102Alibaba (US) Technology Co., Ltd.1,244
AS202736-1,231
AS214143-1,223

The 30 most visible of 233.

138 more neighbours appear on both sides of this network depending on the path, so they are counted in neither list.

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.