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Autonomous System

AS33891 · Core-Backbone GmbH

Overview

RIPE RIS route collectors currently see no prefix originated by AS33891: as far as they can tell, the number is not announced on the Internet right now. In the paths the collectors record, it has 112 upstream neighbours (transit providers or peers) and 2,529 downstream neighbours (customers or networks it carries). Its most visible upstreams are MMC GmbH (AS12577), Nessus GmbH (AS47692), and Datacamp Limited (AS60068). AS33891 was assigned by RIPE NCC, and its registration country is Germany.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 16, 2026 at 8:53 PM UTC. This page is refreshed at most every 12 hours.

Go further

Open in the BGP viewer

No IPv4 address of this network is known right now, so there is nothing to trace to.

Announced prefixes

IPv4 prefixes (none)

None currently seen.

IPv6 prefixes (none)

None currently seen.

Neighbours

Upstreams (transit or peers) (112)

ASNetworkVisibility
AS12577MMC GmbH51,241
AS47692Nessus GmbH50,113
AS60068Datacamp Limited40,016
AS39392SuperNetwork SH.cz s.r.o.39,363
AS1299Arelion Sweden AB16,101
AS49434FBW NETWORKS SAS15,101
AS50673Serverius Holding B.V.11,906
AS3356Level 3 Parent, LLC10,916
AS3257GTT Communications Inc.10,749
AS6939Hurricane Electric LLC6,597
AS50629LWLcom GmbH4,141
AS13030Init7 (Switzerland) Ltd.3,620
AS6461Zayo Bandwidth3,127
AS29691Nine Internet Solutions AG2,671
AS3320Deutsche Telekom AG2,616
AS6830LibertyGlobal Liberty Global Europe Holding B.V.2,417
AS1836-2,112
AS25091IP-Max SA2,035
AS42708Glesys AB1,956
AS50304Blix Solutions AS1,836
AS34177Celeste SAS1,801
AS24961-1,747
AS52320GlobeNet Cabos Submarinos Colombia, S.A.S.1,714
AS8455atom86 BV1,705
AS577Bell Canada1,674
AS35625Eurofiber France SAS1,546
AS12779IT.Gate S.p.A.1,532
AS20764CJSC RASCOM1,518
AS8896GLOBALCONNECT AS1,488
AS21320GEANT Vereniging1,336

The 30 most visible of 112.

Downstreams (customers) (2,529)

ASNetworkVisibility
AS49666Telecommunication Infrastructure Company28,643
AS3356Level 3 Parent, LLC23,418
AS6461Zayo Bandwidth18,662
AS60068Datacamp Limited18,485
AS39392SuperNetwork SH.cz s.r.o.14,920
AS1299Arelion Sweden AB10,496
AS12912T-Mobile Polska S.A.10,053
AS44592SkyLink SkyLink Data Center BV8,854
AS50673Serverius Holding B.V.8,723
AS6939Hurricane Electric LLC8,652
AS59796StormWall s.r.o.8,257
AS88811&1 Versatel GmbH5,908
AS7195EDGEUNO S.A.S5,275
AS3257GTT Communications Inc.5,206
AS4637Telstra Global4,909
AS34779T-2-AS T-2, d.o.o.3,999
AS9498BHARTI Airtel Ltd.3,818
AS37468Angola Cables3,566
AS21413-3,357
AS49434FBW NETWORKS SAS3,282
AS6855-3,153
AS8220COLT Technology Services Group Limited3,094
AS1273IDDQD-AS2,768
AS9121TTNet Turk Telekomunikasyon Anonim Sirketi2,471
AS64049Reliance Jio Infocomm Pte Ltd Singapore2,450
AS267613ELETRONET S.A.2,399
AS3216PJSC "Vimpelcom"2,390
AS47692Nessus GmbH2,272
AS7473Singapore Telecommunications Ltd2,133
AS202425-2,079

The 30 most visible of 2,529.

317 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.