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AS204666Jiri Tlapak

CzechiaRegistryRIPE NCC

As of 10th November 2026, AS204666 (Jiri Tlapak), a network registered in Czechia with RIPE NCC, originates 38 IPv4 prefixes covering 20.7k addresses and 11 IPv6 prefixes. By IPv4 address space that makes it the 7,010th-largest of the 80,723 networks we see originating IPv4, and the 35th-largest of 576 in Czechia. It is seen behind 2 upstream networks, most often AS16019 (Vodafone Czech Republic a.s.) and AS47232 (ISP Alliance a.s.), and in front of 2 downstream networks. Every one of its announcements has a valid RPKI ROA, and none are RPKI-invalid. 100% of its routes reach at least 90% of full-feed peers.

At a glance

IPv4 prefixes

38

IPv6 prefixes

11

IPv4 addresses

20.7k

IPv6 /64s

314B

Upstream graph

The networks AS204666 is seen behind, one and two hops out, drawn from real AS paths.

AS204666Toward the internet core
Upstream graph for AS204666: 5 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS204666Jiri TlapakThis networkAS16019Vodafone Czech Re…AS47232ISP Alliance a.s.AS1273Vodafone Group PLCAS6939Hurricane Electri…AS1299Arelion (fka. Tel…

Networks observed one and two hops upstream of AS204666 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.

Neighbouring networks

8

adjacent networks

Upstreams
225%
Peers
450%
Downstreams
225%

Networks carrying this one's traffic toward the rest of the internet.

Upstreams of AS204666
NetworkCountryRelationshipPathsVantage pts
AS16019Vodafone Czech Republic a.s.CZPeer3,042137
AS47232ISP Alliance a.s.CZPeer70970

Prefixes

All 49

The largest blocks AS204666 originates, widest first.

Largest prefixes originated by AS204666
PrefixAddressesVisibility
37.221.240.0/204.1k76/76
45.153.192.0/221k76/76
85.255.88.0/221k76/76
185.19.0.0/221k76/76
185.64.220.0/221k76/76
185.87.140.0/221k76/76
185.97.24.0/221k76/76
185.230.172.0/221k76/76
185.243.172.0/221k76/76
5.59.102.0/2351276/76

Routing health

How AS204666's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.

RPKI origin validation

  • Valid100.0%49
  • Invalid0.0%0
  • No ROA0.0%0

Propagation

  • Globally propagated90% of full-feed peers or more100.0%49
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 38 prefixes

IPv6 — 11 prefixes

  • /2934.4B × /6481.8%9
  • /324.3B × /649.1%1
  • /4865.5k × /649.1%1

Recent changes

Announcements that started or stopped since 11th Oct 2026.

Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.