Country
Czechia
Autonomous systems registered in Czechia, largest IPv4 address space first.
Routed networks
600
of 716 registered
IPv4 addresses
11.22M
2,378 prefixes
IPv6 prefixes
986
CZ
Networks
| AS | Network | IPv4 addresses | IPv4 prefixes | IPv6 prefixes | Upstreams | Downstreams |
|---|---|---|---|---|---|---|
| AS5610 | O2 Czech Republic, a.s. | 2.33M | 67 | 5 | 10 | 43 |
| AS16019 | Vodafone Czech Republic a.s. | 2.30M | 90 | 17 | 10 | 91 |
| AS13036 | T-Mobile Czech Republic a.s. | 992K | 34 | 3 | 1 | 0 |
| AS2852 | CESNET z.s.p.o. | 858K | 26 | 1 | 26 | 19 |
| AS44546 | ALFA TELECOM s.r.o. | 528K | 14 | 0 | 4 | 0 |
| AS2571 | DHL Information Services (Europe) s.r.o | 439K | 55 | 46 | 8 | 0 |
| AS29208 | Quantcom, a.s. | 274K | 36 | 5 | 25 | 63 |
| AS28725 | CETIN a.s. | 265K | 9 | 2 | 34 | 35 |
| AS30764 | PODA a.s. | 219K | 16 | 2 | 11 | 7 |
| AS42908 | O2 Czech Republic, a.s. | 183K | 35 | 9 | 1 | 2 |
| AS16246 | O2 Czech Republic, a.s. | 133K | 13 | 2 | 1 | 13 |
| AS25512 | CD-Telematika a.s. | 118K | 11 | 1 | 7 | 24 |
| AS15425 | PODA a.s. | 111K | 8 | 1 | 1 | 0 |
| AS25248 | RADIOKOMUNIKACE a.s. | 107K | 5 | 2 | 7 | 27 |
| AS44489 | STARNET, s.r.o. | 77.31K | 26 | 7 | 9 | 3 |
| AS197451 | Brno University of Technology | 67.58K | 8 | 4 | 3 | 8 |
| AS31246 | O2 Czech Republic, a.s. | 66.56K | 5 | 2 | 1 | 0 |
| AS24971 | MasterDC s.r.o. | 58.88K | 33 | 13 | 9 | 8 |
| AS12570 | O2 Czech Republic, a.s. | 53.76K | 11 | 2 | 1 | 9 |
| AS41046 | O2 Czech Republic, a.s. | 53.25K | 8 | 2 | 1 | 0 |
| AS15935 | ha-vel internet s.r.o. | 51.97K | 13 | 3 | 14 | 15 |
| AS24806 | INTERNET CZ, a.s. | 45.82K | 11 | 1 | 8 | 0 |
| AS6740 | CEZNET s.r.o. | 41.98K | 4 | 0 | 1 | 0 |
| AS21430 | WIA spol. s.r.o. | 41.47K | 65 | 5 | 11 | 9 |
| AS39906 | CoProSys a.s. | 37.89K | 11 | 2 | 1 | 1 |
| AS25424 | CEZNET s.r.o. | 33.79K | 7 | 2 | 6 | 3 |
| AS39392 | SH.cz s.r.o. | 32.51K | 12 | 5 | 12 | 100 |
| AS15685 | CASABLANCA INT a.s. | 31.74K | 59 | 1 | 7 | 7 |
| AS9080 | Ipex A.S | 26.62K | 5 | 1 | 8 | 1 |
| AS29134 | Webglobe, s.r.o. | 25.60K | 23 | 5 | 8 | 3 |
| AS43709 | SilesNet s.r.o. | 24.58K | 7 | 7 | 11 | 0 |
| AS35592 | Coolhousing s.r.o. | 23.30K | 31 | 4 | 7 | 5 |
| AS50698 | TETA s.r.o. | 22.53K | 9 | 3 | 9 | 0 |
| AS204666 | Jiri Tlapak | 20.74K | 38 | 11 | 2 | 2 |
| AS51420 | cyrilek.net z.s. | 20.48K | 18 | 0 | 2 | 0 |
| AS42306 | CEZNET s.r.o. | 20.48K | 8 | 4 | 7 | 2 |
| AS15614 | Dragon Internet a.s. | 19.97K | 6 | 1 | 9 | 2 |
| AS39791 | Telco Pro Services, a. s. | 18.69K | 3 | 2 | 6 | 10 |
| AS24641 | FASTER CZ spol. s r.o. | 18.43K | 10 | 2 | 6 | 13 |
| AS49985 | IP4ISP z.s.p.o | 17.92K | 6 | 1 | 3 | 0 |
| AS8251 | FreeTel, s.r.o. | 17.41K | 6 | 1 | 7 | 16 |
| AS61296 | TechCom s.r.o. | 17.41K | 2 | 1 | 8 | 0 |
| AS43541 | VSHosting s.r.o. | 17.15K | 18 | 7 | 5 | 12 |
| AS196735 | PODA a.s. | 16.64K | 2 | 1 | 7 | 4 |
| AS20723 | AVONET, s.r.o. | 16.38K | 7 | 1 | 8 | 1 |
| AS49101 | CEZNET s.r.o. | 16.38K | 2 | 2 | 1 | 3 |
| AS196822 | SELECT SYSTEM, s.r.o. | 16.38K | 1 | 1 | 2 | 0 |
| AS197197 | CETIN a.s. | 16.38K | 1 | 1 | 1 | 0 |
| AS57728 | CEZNET s.r.o. | 15.36K | 5 | 3 | 1 | 0 |
| AS29321 | O2 Czech Republic, a.s. | 15.36K | 5 | 1 | 1 | 0 |
| AS207187 | TKR Jasek, s.r.o. | 14.34K | 6 | 3 | 10 | 8 |
| AS210712 | ISP Alliance a.s. | 14.34K | 7 | 1 | 1 | 1 |
| AS51248 | Host-Telecom.com s.r.o. | 14.08K | 20 | 5 | 11 | 4 |
| AS34040 | TTNET s.r.o. | 13.82K | 4 | 1 | 1 | 0 |
| AS207700 | Reliable Communications s.r.o. | 13.06K | 26 | 0 | 2 | 0 |
| AS28972 | M-SOFT, spol. s r.o. | 12.80K | 6 | 2 | 8 | 1 |
| AS35236 | UVT Internet s.r.o. | 12.29K | 12 | 7 | 12 | 7 |
| AS48926 | Pe3ny Net s.r.o. | 12.29K | 6 | 1 | 1 | 0 |
| AS197013 | Sprintel s.r.o. | 12.29K | 5 | 1 | 7 | 1 |
| AS43507 | RETE internet, s.r.o. | 12.29K | 2 | 0 | 8 | 0 |
| AS56566 | SATT a.s. | 12.03K | 9 | 1 | 2 | 0 |
| AS204383 | SPCom s.r.o. | 11.26K | 19 | 1 | 1 | 1 |
| AS34080 | MIRAMO spol. s.r.o. | 11.26K | 4 | 1 | 6 | 1 |
| AS47114 | SychrovNET s.r.o | 10.75K | 5 | 2 | 8 | 0 |
| AS201730 | Cloud4com s.r.o. | 10.50K | 26 | 1 | 6 | 0 |
| AS39761 | ABAK, Co.Ltd. | 10.24K | 6 | 2 | 2 | 1 |
| AS197019 | WEDOS Internet, a.s. | 10.24K | 4 | 2 | 7 | 1 |
| AS47232 | ISP Alliance a.s. | 9.98K | 10 | 6 | 9 | 57 |
| AS39790 | Web4U s.r.o. | 9.73K | 5 | 3 | 6 | 0 |
| AS50833 | FIBER TELECOM s.r.o. | 9.22K | 10 | 5 | 11 | 0 |
| AS35613 | FASTER CZ spol. s r.o. | 9.22K | 5 | 2 | 3 | 1 |
| AS41088 | "N_SYS s.r.o." | 9.22K | 2 | 2 | 1 | 0 |
| AS48574 | T-Mobile Czech Republic a.s. | 9.22K | 3 | 0 | 1 | 0 |
| AS197798 | Net-Connect s.r.o. | 9.22K | 2 | 1 | 2 | 0 |
| AS201476 | ISP Alliance a.s. | 8.70K | 13 | 2 | 1 | 0 |
| AS43070 | JAW.cz s.r.o. | 8.70K | 6 | 3 | 10 | 0 |
| AS50825 | UVT Internet s.r.o. | 8.45K | 6 | 1 | 1 | 0 |
| AS29086 | GiTy, a.s. | 8.19K | 5 | 1 | 7 | 0 |
| AS47269 | Core4Net, s.r.o. | 8.19K | 5 | 1 | 1 | 0 |
| AS57188 | ORKA systems, s.r.o. | 8.19K | 3 | 1 | 2 | 0 |
| AS57279 | Sauron CZ s.r.o. | 8.19K | 3 | 1 | 8 | 0 |
| AS8913 | Mopos Communications A.S. | 8.19K | 1 | 1 | 6 | 0 |
| AS33943 | Quadruple a.s. | 8.19K | 1 | 1 | 1 | 0 |
| AS43542 | OptoNet Communication, spol. s.r.o. | 8.19K | 1 | 1 | 7 | 4 |
| AS47493 | CEZNET s.r.o. | 8.19K | 1 | 1 | 1 | 0 |
| AS198002 | CEZNET s.r.o. | 8.19K | 1 | 1 | 1 | 0 |
| AS202237 | Wic-Net, s.r.o. | 8.19K | 1 | 1 | 1 | 0 |
| AS57069 | Dempsey and Clark s.r.o. | 8.19K | 1 | 0 | 1 | 0 |
| AS25234 | ACTIVE 24, s.r.o. | 7.68K | 5 | 3 | 10 | 1 |
| AS35046 | OMEGA plus Chrudim s.r.o. | 7.17K | 3 | 2 | 4 | 2 |
| AS42189 | Druzstvo EUROSIGNAL | 7.17K | 4 | 1 | 2 | 1 |
| AS33883 | TRIOPTIMUM s.r.o. | 7.17K | 3 | 1 | 1 | 1 |
| AS28905 | OMEGA plus Chrudim s.r.o. | 7.17K | 3 | 0 | 1 | 0 |
| AS49121 | Infinity Telecom, s.r.o. | 6.91K | 20 | 8 | 38 | 11 |
| AS202895 | TFnet s.r.o. | 6.91K | 10 | 1 | 7 | 0 |
| AS60592 | Gransy s.r.o. | 6.66K | 18 | 3 | 15 | 0 |
| AS25192 | CZ.NIC, z.s.p.o. | 6.66K | 8 | 6 | 39 | 7 |
| AS197296 | United Networks SE | 6.66K | 4 | 1 | 1 | 0 |
| AS42000 | Futruy s.r.o. | 6.40K | 5 | 1 | 7 | 13 |
| AS59479 | GEMNET s.r.o. | 6.40K | 3 | 1 | 1 | 1 |
Registration country comes from the regional registries' delegation files. A network registered here may announce space used anywhere.