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Czechia
Networks in Czechia
599 autonomous systems are registered in Czechia (CZ). Together they announce 8,275,712 IPv4 addresses, 0.26% of the announced total, which ranks Czechia #40 of 240 countries.
Autonomous systems 599 570 announce IPv4, 29 IPv6 only
IPv4 addresses 8,275,712 0.26% of announced IPv4 · #40 worldwide
Top 5 networks hold 58.7% of Czechia's IPv4 space
IPv6 1,894 x /32 (124,143,210 x /48) 432 of 599 networks (72%) announce IPv6
Small networks 89 announce a single /24 (256 addresses) or less
Top 50 networks in Czechia by IPv4 space
# ASN Network IPv4 addresses Of CZ
1
AS5610 O2-CZECH-REPUBLIC O2 Czech Republic, a.s.
1,540,608
18.62%
2
AS16019 VODAFONE-CZ-AS Vodafone Czech Republic a.s.
1,210,368
14.63%
3
AS13036 TMOBILE-CZ T-Mobile Czech Republic a.s.
992,256
11.99%
4
AS2852 CESNET2 CESNET z.s.p.o.
849,920
10.27%
5
AS29208 QUANTCOM-AS Quantcom, a.s.
265,984
3.21%
6
AS30764 PODA-AS PODA a.s.
218,112
2.64%
7
AS42908 CZ-NORDICTELECOMREGIONAL O2 Czech Republic, a.s.
183,296
2.21%
8
AS2571 DHLNET - DHL Information Services (Europe) s.r.o
152,832
1.85%
9
AS28725 CETIN-AS CETIN a.s.
134,400
1.62%
10
AS16246 AS16246 O2 Czech Republic, a.s.
133,120
1.61%
11
AS25512 CDT-AS CD-Telematika a.s.
117,760
1.42%
12
AS44546 ALFATELECOM-AS ALFA TELECOM s.r.o.
110,848
1.34%
13
AS15425 COMA PODA a.s.
110,592
1.34%
14
AS25248 BlueTone-AS RADIOKOMUNIKACE a.s.
106,752
1.29%
15
AS197451 VUTBR-AS Brno University of Technology
66,816
0.81%
16
AS31246 NETBOX-AS O2 Czech Republic, a.s.
66,560
0.80%
17
AS44489 Starnet STARNET, s.r.o.
64,768
0.78%
18
AS24971 MASTER-AS MasterDC s.r.o.
58,112
0.70%
19
AS15935 HA-VEL-LOCAL-AS ha-vel internet s.r.o.
50,432
0.61%
20
AS12570 ITSELF O2 Czech Republic, a.s.
49,664
0.60%
21
AS24806 INTERNET-CZ INTERNET CZ, a.s.
45,824
0.55%
22
AS6740 INEXT-CZ-ADA CEZNET s.r.o.
41,984
0.51%
23
AS21430 WIA-AS WIA spol. s.r.o.
41,216
0.50%
24
AS25424 INEXT-CZ CEZNET s.r.o.
33,792
0.41%
25
AS39906 COPROSYS CoProSys a.s.
33,792
0.41%
26
AS41046 NEJTV-AS O2 Czech Republic, a.s.
32,768
0.40%
27
AS39392 SuperNetwork SH.cz s.r.o.
31,744
0.38%
28
AS15685 CASABLANCA-AS CASABLANCA INT a.s.
31,232
0.38%
29
AS9080 GIN Ipex A.S
26,624
0.32%
30
AS29134 IGNUM-AS Webglobe, s.r.o.
21,248
0.26%
31
AS42306 EDERA_Group CEZNET s.r.o.
20,480
0.25%
32
AS15614 Dragon Dragon Internet a.s.
19,968
0.24%
33
AS39791 TPS-AS Telco Pro Services, a. s.
18,688
0.23%
34
AS49985 IP4ISP IP4ISP z.s.p.o
17,920
0.22%
35
AS8251 NFX_ZSPO FreeTel, s.r.o.
17,408
0.21%
36
AS61296 TechCom-AS TechCom s.r.o.
17,408
0.21%
37
AS43541 VSHOSTING VSHosting s.r.o.
17,152
0.21%
38
AS24641 FASTER-AS FASTER CZ spol. s r.o.
16,896
0.20%
39
AS20723 MGI AVONET, s.r.o.
16,384
0.20%
40
AS196735 AS-JONCZ PODA a.s.
16,384
0.20%
41
AS196822 SELECTSYSTEM-AS SELECT SYSTEM, s.r.o.
16,384
0.20%
42
AS197197 M-NET CETIN a.s.
16,384
0.20%
43
AS57728 CEZNET-AS CEZNET s.r.o.
15,360
0.19%
44
AS29321 CentroNetAS O2 Czech Republic, a.s.
15,360
0.19%
45
AS204666 TLAPNET-CZ Jiri Tlapak
14,336
0.17%
46
AS207187 TKRJASEK TKR Jasek, s.r.o.
14,336
0.17%
47
AS210712 GRAPESC-ISP ISP Alliance a.s.
14,336
0.17%
48
AS51248 HOST-TELECOM Host-Telecom.com s.r.o.
14,080
0.17%
49
AS207700 Reliable-Communications Reliable Communications s.r.o.
14,080
0.17%
50
AS35592 COOLHOUSING-AS Coolhousing s.r.o.
13,568
0.16%
Countries of similar size
IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources