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AS42908O2 Czech Republic, a.s.

CzechiaRegistryRIPE NCC

As of 29th September 2026, AS42908 (O2 Czech Republic, a.s.), a network registered in Czechia with RIPE NCC, originates 35 IPv4 prefixes covering 183k addresses and 9 IPv6 prefixes. By IPv4 address space that makes it the 1,450th-largest of the 79,607 networks we see originating IPv4, and the 10th-largest of 574 in Czechia. It is seen behind 1 upstream network, most often AS5610 (O2 Czech Republic, 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

35

IPv6 prefixes

9

IPv4 addresses

183k

IPv6 /64s

159B

Upstream graph

The networks AS42908 is seen behind, one and two hops out, drawn from real AS paths.

AS42908Toward the internet core
Upstream graph for AS42908: 3 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS42908O2 Czech Republic…This networkAS5610O2 Czech Republic…AS174Cogent Communicat…AS1299Arelion (fka. Tel…

Networks observed one and two hops upstream of AS42908 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

6

adjacent networks

Upstreams
117%
Peers
350%
Downstreams
233%

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

Upstreams of AS42908
NetworkCountryRelationshipPathsVantage pts
AS5610O2 Czech Republic, a.s.CZPeer3,511145

Prefixes

All 44

The largest blocks AS42908 originates, widest first.

Largest prefixes originated by AS42908
PrefixAddressesVisibility
213.19.0.0/1732.8k81/82
78.136.128.0/1816.4k80/82
94.241.64.0/1816.4k81/82
213.250.192.0/1816.4k81/82
88.81.64.0/198.2k80/82
91.187.32.0/198.2k81/82
109.108.96.0/198.2k81/82
176.102.128.0/198.2k81/82
213.155.32.0/198.2k81/82
5.102.48.0/204.1k81/82

Routing health

How AS42908'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%44
  • Invalid0.0%0
  • No ROA0.0%0

Propagation

  • Globally propagated90% of full-feed peers or more100.0%44
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 35 prefixes

IPv6 — 9 prefixes

  • /2934.4B × /6444.4%4
  • /324.3B × /6455.6%5

Recent changes

Announcements that started or stopped since 30th Aug 2026.

No announcement by AS42908 started or stopped in this period.

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