Czechia
Autonomous systems and IP prefixes registered in Czechia.
Registered ASNs
716
IPv4 Prefixes
52,399
IPv6 Prefixes
7,550
Largest Networksby registered prefixes
| # | ASN | Name | Prefixes |
|---|---|---|---|
| 1 | AS24971 | RIPENCCMASTER-AS MasterDC s.r.o. | 178 |
| 2 | AS208414 | RIPENCCWEDOS-GLOBAL WEDOS Internet, a.s. | 123 |
| 3 | AS212234 | RIPENCCSMEJKALOVA SMEJKALOVA Marketa | 69 |
| 4 | AS21430 | RIPENCCWIA-AS WIA spol. s.r.o. | 67 |
| 5 | AS15685 | RIPENCCCASABLANCA-AS CASABLANCA INT a.s. | 62 |
| 6 | AS16019 | RIPENCCVODAFONE-CZ-AS Vodafone Czech Republic a.s. | 59 |
| 7 | AS198605 | RIPENCCAVAST-AS-DC AVAST Software s.r.o. | 46 |
| 8 | AS42908 | RIPENCCCZ-NORDICTELECOMREGIONAL O2 Czech Republic, a.s. | 44 |
| 9 | AS25512 | RIPENCCCDT-AS CD-Telematika a.s. | 43 |
| 10 | AS214757 | RIPENCCJakub-Krsa Jakub Krsa | 43 |
| 11 | AS5610 | RIPENCCO2-CZECH-REPUBLIC O2 Czech Republic, a.s. | 42 |
| 12 | AS13036 | RIPENCCTMOBILE-CZ T-Mobile Czech Republic a.s. | 38 |
| 13 | AS29208 | RIPENCCQUANTCOM-AS Quantcom, a.s. | 38 |
| 14 | AS204666 | RIPENCCTLAPNET-CZ Jiri Tlapak | 32 |
| 15 | AS2852 | RIPENCCCESNET2 CESNET z.s.p.o. | 28 |
| 16 | AS44489 | RIPENCCStarnet STARNET, s.r.o. | 28 |
| 17 | AS51248 | RIPENCCHOST-TELECOM Host-Telecom.com s.r.o. | 26 |
| 18 | AS49121 | RIPENCCINFTELE-AS Infinity Telecom, s.r.o. | 25 |
| 19 | AS207700 | RIPENCCReliable-Communications Reliable Communications s.r.o. | 25 |
| 20 | AS200449 | RIPENCCQRATOR-CZ Qrator Labs CZ s.r.o. | 24 |
| 21 | AS201730 | RIPENCCDataSpring Cloud4com s.r.o. | 23 |
| 22 | AS209369 | RIPENCCTCPRO The Cloud Provider s.r.o. | 22 |
| 23 | AS198668 | RIPENCCTLAPNET-CZ Tlapnet s.r.o. | 21 |
| 24 | AS206438 | RIPENCCMXNET-AS MX-NET Telekomunikace s.r.o. | 21 |
| 25 | AS39906 | RIPENCCCOPROSYS CoProSys a.s. | 20 |
| 26 | AS43541 | RIPENCCVSHOSTING VSHosting s.r.o. | 20 |
| 27 | AS204150 | RIPENCCStormHost David Zakoucky | 20 |
| 28 | AS204383 | RIPENCCCZ-SPCOM-AS SPCom s.r.o. | 20 |
| 29 | AS5588 | RIPENCCGTSCE T-Mobile Czech Republic a.s. | 19 |
| 30 | AS29134 | RIPENCCIGNUM-AS Webglobe, s.r.o. | 19 |
| 31 | AS30764 | RIPENCCPODA-AS PODA a.s. | 19 |
| 32 | AS60592 | RIPENCCGRANSY Gransy s.r.o. | 19 |
| 33 | AS2118 | RIPENCCRELCOM-AS Reliable Communications s.r.o. | 18 |
| 34 | AS24806 | RIPENCCINTERNET-CZ INTERNET CZ, a.s. | 18 |
| 35 | AS209155 | RIPENCConehostplanet Onehostplanet s.r.o. | 17 |
| 36 | AS15935 | RIPENCCHA-VEL-LOCAL-AS ha-vel internet s.r.o. | 16 |
| 37 | AS29504 | RIPENCCLBCFREE Freenet Liberec, z.s. | 16 |
| 38 | AS35236 | RIPENCCAS35236 UVT Internet s.r.o. | 16 |
| 39 | AS44002 | RIPENCCSYS-DATACOM Sys-DataCom s.r.o. | 16 |
| 40 | AS197029 | RIPENCCLAM-AS LAM plus s.r.o. | 16 |
| 41 | AS203488 | RIPENCCDALUNET DaLuNET s.r.o. | 16 |
| 42 | AS203645 | RIPENCCRYZNAR-AS Jan Ryznar | 16 |
| 43 | AS16246 | RIPENCCAS16246 O2 Czech Republic, a.s. | 15 |
| 44 | AS39904 | RIPENCCMERIT-AS MERIT GROUP a.s | 15 |
| 45 | AS204860 | RIPENCCNETX NetX Networks a.s. | 15 |
| 46 | AS210951 | RIPENCCMIEGLNET Josef Miegl | 15 |
| 47 | AS35136 | RIPENCCLVIV-IX-AS Global Tech Distribution s.r.o. | 14 |
| 48 | AS35592 | RIPENCCCOOLHOUSING-AS Coolhousing s.r.o. | 14 |
| 49 | AS39392 | RIPENCCSuperNetwork SH.cz s.r.o. | 14 |
| 50 | AS199711 | RIPENCCNCISA-AS National Cyber and Information Security Agency | 14 |
| 51 | AS201476 | RIPENCCWolfnet ISP Alliance a.s. | 14 |
| 52 | AS216241 | RIPENCCVSB_CZ Vysoka skola banska - Technicka univerzita Ostrava | 14 |
| 53 | AS31349 | RIPENCCa-net a-net Liberec s.r.o. | 13 |
| 54 | AS44546 | RIPENCCALFATELECOM-AS ALFA TELECOM s.r.o. | 13 |
| 55 | AS47232 | RIPENCCISPAlliance ISP Alliance a.s. | 13 |
| 56 | AS47317 | RIPENCCWEB4CE Web4ce, s.r.o. | 13 |
| 57 | AS50833 | RIPENCCFIBERTEL-AS FIBER TELECOM s.r.o. | 13 |
| 58 | AS62178 | RIPENCCMaster_IT_Technologies MASTER IT Technologies, a.s. | 13 |
| 59 | AS200828 | RIPENCCTHOSTING-AS TERMS a.s. | 13 |
| 60 | AS200918 | RIPENCCORELSOFT Pavel Zizka | 13 |
| 61 | AS12570 | RIPENCCITSELF O2 Czech Republic, a.s. | 12 |
| 62 | AS30738 | RIPENCCNETART-AS NetArt Group s.r.o. | 12 |
| 63 | AS42422 | RIPENCCSECURITYNET-AS SecurityNet.cz s.r.o. | 12 |
| 64 | AS198101 | RIPENCCKOOPERATIVA-AS Kooperativa pojistovna, a.s., Vienna Insurance Group | 12 |
| 65 | AS39790 | RIPENCCWEB4U Web4U s.r.o. | 11 |
| 66 | AS42306 | RIPENCCEDERA_Group CEZNET s.r.o. | 11 |
| 67 | AS50698 | RIPENCCTETA TETA s.r.o. | 11 |
| 68 | AS50825 | RIPENCCUVT UVT Internet s.r.o. | 11 |
| 69 | AS199734 | RIPENCCPetr Petr Kyvala | 11 |
| 70 | AS24641 | RIPENCCFASTER-AS FASTER CZ spol. s r.o. | 10 |
| 71 | AS25234 | RIPENCCACTIVE24-AS ACTIVE 24, s.r.o. | 10 |
| 72 | AS43500 | RIPENCCWBD-AS HBO Europe s.r.o. | 10 |
| 73 | AS48298 | RIPENCCGOVCZ MINISTERSTVO VNITRA CR | 10 |
| 74 | AS56566 | RIPENCCSATT-AS SATT a.s. | 10 |
| 75 | AS197451 | RIPENCCVUTBR-AS Brno University of Technology | 10 |
| 76 | AS207242 | RIPENCCNOEL NOEL, s.r.o. | 10 |
| 77 | AS15425 | RIPENCCCOMA PODA a.s. | 9 |
| 78 | AS25192 | RIPENCCCZNIC-AS CZ.NIC, z.s.p.o. | 9 |
| 79 | AS25424 | RIPENCCINEXT-CZ CEZNET s.r.o. | 9 |
| 80 | AS39761 | RIPENCCABAK ABAK, Co.Ltd. | 9 |
| 81 | AS43037 | RIPENCCSEZNAM-CZ Seznam.cz, a.s. | 9 |
| 82 | AS44065 | RIPENCCNETAIR-AS NETAIR, s.r.o. | 9 |
| 83 | AS51331 | RIPENCCModernTV SychrovNET s.r.o | 9 |
| 84 | AS57707 | RIPENCCGREENDATA Greendata s.r.o. | 9 |
| 85 | AS198167 | RIPENCCAppToCloud Apptc.me s.r.o. | 9 |
| 86 | AS198813 | RIPENCCSychrovNET SychrovNET s.r.o | 9 |
| 87 | AS201648 | RIPENCCPLZ-AS-CZ Plzensky kraj | 9 |
| 88 | AS207187 | RIPENCCTKRJASEK TKR Jasek, s.r.o. | 9 |
| 89 | AS210712 | RIPENCCGRAPESC-ISP ISP Alliance a.s. | 9 |
| 90 | AS215704 | RIPENCCNGN-CZ NGN CZ s.r.o. | 9 |
| 91 | AS20723 | RIPENCCMGI AVONET, s.r.o. | 8 |
| 92 | AS28972 | RIPENCCMSOFT-AS M-SOFT, spol. s r.o. | 8 |
| 93 | AS48417 | RIPENCCITS-CZ ITS akciova spolecnost | 8 |
| 94 | AS48926 | RIPENCCPE3NY-AS Pe3ny Net s.r.o. | 8 |
| 95 | AS49985 | RIPENCCIP4ISP IP4ISP z.s.p.o | 8 |
| 96 | AS196943 | RIPENCCASVISSADO Vissado s.r.o. | 8 |
| 97 | AS197013 | RIPENCCSPRINTEL-SRO Sprintel s.r.o. | 8 |
| 98 | AS204949 | RIPENCCCMIS CMIS s.r.o. | 8 |
| 99 | AS206712 | RIPENCCFeldHost-AS FELDSAM s.r.o. | 8 |
| 100 | AS2571 | ARINDHLNET - DHL Information Services (Europe) s.r.o | 7 |
Threat map: malicious IPs in Czechia
38 flagged IPv4 networks on 2026-10-10, #56 of 176 countries; 3.96 per million allocated IPv4 addresses (#62 by rate).
IP Address Transfers
Last 12 months: 146 registry transfers involving organisations in Czechia, 173K IPv4 addresses.
IPv4 received from
- 1🇺🇸 United States21K
- 2🇩🇪 Germany17K
- 3🇮🇪 Ireland8,192
- 4🇬🇧 United Kingdom1,536
- 5🇪🇸 Spain1,024
IPv4 sent to
- 1🇷🇺 Russia12K
- 2🇹🇷 Türkiye4,096
- 3🇪🇪 Estonia1,024
- 4🇺🇸 United States512
- 5🇬🇧 United Kingdom512
- 2a07:4c0::/29M&A ·
- 2a03:f280::/29M&A ·
- 77.236.192.0/19M&A ·
- 37.44.208.0/22M&A ·
- 185.137.144.0/22M&A ·
- AS42306M&A ·
- 2a06:ed40::/29M&A ·
- 185.134.160.0/22M&A ·
- AS203450M&A ·
- 2a0e:5340::/29M&A ·
| Date | Resource | From | To | Type |
|---|---|---|---|---|
| 2a07:4c0::/29 | M&A | |||
| 2a03:f280::/29 | M&A | |||
| 77.236.192.0/19 | M&A | |||
| 37.44.208.0/22 | M&A | |||
| 185.137.144.0/22 | M&A | |||
| AS42306 | M&A | |||
| 2a06:ed40::/29 | M&A | |||
| 185.134.160.0/22 | M&A | |||
| AS203450 | M&A | |||
| 2a0e:5340::/29 | M&A |