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Autonomous System

AS1921 · ipcom GmbH

Overview

AS1921 is announced on the Internet: RIPE RIS route collectors currently see 16 IPv4 prefixes and 16 IPv6 prefixes originated by this network. Together, its IPv4 prefixes cover 4,096 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 55 upstream neighbours (transit providers or peers) and 3 downstream neighbours (customers or networks it carries). Its most visible upstreams are ScaleUp Technologies GmbH & Co. KG (AS29014), Gigahost AS (AS56655), and Hurricane Electric LLC (AS6939). AS1921 was assigned by ARIN, and its registration country is Austria.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 17, 2026 at 3:15 AM UTC. This page is refreshed at most every 12 hours.

Go further

The trace goes to 91.237.67.1, the first address of 91.237.67.0/24. 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 (16 prefixes)

PrefixAddresses
91.237.67.0/24256
176.97.158.0/24256
185.80.188.0/24256
185.80.190.0/24256
185.80.191.0/24256
185.102.12.0/24256
185.167.176.0/24256
192.174.68.0/24256
193.46.128.0/24256
193.46.133.0/24256
193.46.134.0/24256
193.46.135.0/24256
193.227.117.0/24256
194.0.25.0/24256
194.0.182.0/24256
194.50.187.0/24256

IPv6 prefixes (16 prefixes)

Prefix
2001:678:20::/48
2001:67c:1bc::/48
2001:67c:10b8::/48
2a02:850:ffe0::/48
2a02:850:ffe5::/48
2a02:850:ffe6::/48
2a02:850:ffe7::/48
2a02:850:ffff::/48
2a04:2b00:14cc::/48
2a04:2b00:14dd::/48
2a04:2b00:14ee::/48
2a05:7f00:188::/48
2a05:7f00:190::/48
2a05:7f00:191::/48
2a0b:8e00::/48
2a0b:8e00:1::/48

Neighbours

Upstreams (transit or peers) (55)

ASNetworkVisibility
AS29014ScaleUp Technologies GmbH & Co. KG357
AS56655Gigahost AS342
AS6939Hurricane Electric LLC299
AS20473The Constant Company, LLC221
AS5459London Internet Exchange Ltd.139
AS44066firstcolo GmbH79
AS49544i3Dnet i3D.net B.V63
AS29222Infomaniak Network SA40
AS42473Anexia Cloud Solutions GmbH31
AS7195EDGEUNO S.A.S29
AS30971-28
AS36236-18
AS42708Glesys AB17
AS22548Nucleo de Inf. e Coord. do Ponto BR - NIC.BR16
AS8849-15
AS56630Melbikomas UAB15
AS25091IP-Max SA12
AS55803-10
AS199524G-Core Labs S.A.10
AS33891Core-Backbone GmbH8
AS5405Inter.link GmbH7
AS9002RETN Limited6
AS34549meerfarbig GmbH & Co. KG6
AS34927iFog GmbH5
AS35280F5 Networks SARL5
AS42310-5
AS50304Blix Solutions AS5
AS8308NAUKOWA I AKADEMICKA SIEC KOMPUTEROWA - PANSTWOWY INSTYTUT BADAWCZY4
AS12779IT.Gate S.p.A.4
AS29075IELO-LIAZO SERVICES SAS4

The 30 most visible of 55.

Downstreams (customers) (3)

ASNetworkVisibility
AS35052ACONET144
AS11644Nucleo de Inf. e Coord. do Ponto BR - NIC.BR29
AS12136Nucleo de Inf. e Coord. do Ponto BR - NIC.BR7

55 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.