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Autonomous System

AS25512 · CD-Telematika a.s.

Overview

AS25512 is announced on the Internet: RIPE RIS route collectors currently see 11 IPv4 prefixes and 1 IPv6 prefix originated by this network. Together, its IPv4 prefixes cover 117,760 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 13 upstream neighbours (transit providers or peers) and 32 downstream neighbours (customers or networks it carries). Its most visible upstreams are Arelion Sweden AB (AS1299), Cogent Communications, LLC (AS174), and Hurricane Electric LLC (AS6939). AS25512 was assigned by RIPE NCC, and its registration country is Czechia.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 17, 2026 at 3:48 AM UTC. This page is refreshed at most every 12 hours.

Go further

Trace a route to this networkOpen in the BGP viewerWHOIS of 89.203.128.1

The trace goes to 89.203.128.1, the first address of 89.203.128.0/17. 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 (11 prefixes)

PrefixAddresses
81.19.32.0/204,096
82.117.128.0/198,192
82.202.64.0/1816,384
85.13.64.0/1816,384
85.184.16.0/204,096
89.203.128.0/1732,768
131.117.192.0/212,048
185.134.0.0/221,024
195.146.96.0/198,192
212.11.96.0/198,192
213.235.128.0/1816,384

IPv6 prefixes (1 prefix)

Prefix
2001:1a48::/32

Neighbours

Upstreams (transit or peers) (13)

ASNetworkVisibility
AS1299Arelion Sweden AB2,263
AS174Cogent Communications, LLC1,621
AS6939Hurricane Electric LLC495
AS6461Zayo Bandwidth113
AS8218Zayo Infrastructure France SA60
AS33891Core-Backbone GmbH51
AS1764Next Layer Telekommunikationsdienstleistungs- und Beratungs GmbH38
AS14840BR.Digital Telecom38
AS6204INTERKVM HOST SRL17
AS4455IX Reach Ltd16
AS22356Durand do Brasil Ltda15
AS6663-12
AS21215UNITED GROUP NETWORK INFRASTRUCTURE d.o.o. Beograd10

Downstreams (customers) (32)

ASNetworkVisibility
AS174Cogent Communications, LLC8,200
AS1299Arelion Sweden AB1,633
AS6461Zayo Bandwidth554
AS20609kazaczsro KAZA.cz s.r.o.456
AS43614Economia a.s.342
AS206159Fresh Data s.r.o.333
AS56450Alberon Letohrad s.r.o301
AS200828TERMS a.s.291
AS43507RETE internet, s.r.o.253
AS51524Ales Tesacek252
AS197550-252
AS3161-251
AS56827-251
AS200355-251
AS47131-202
AS50975-190
AS213387-184
AS47868-165
AS6204INTERKVM HOST SRL124
AS56717-115
AS20708-99
AS51331-95
AS60275-78
AS6881-47
AS216450-16
AS48417-12
AS35046-5
AS51449-3
AS44306-2
AS1764Next Layer Telekommunikationsdienstleistungs- und Beratungs GmbH1

The 30 most visible of 32.

9 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.