subnet.im

AS2852CESNET z.s.p.o.

CzechiaRegistryRIPE NCCTypeEyeball

As of 11th November 2026, AS2852 (CESNET z.s.p.o.), an access network registered in Czechia with RIPE NCC, originates 26 IPv4 prefixes covering 858k addresses and 1 IPv6 prefix. By IPv4 address space that makes it the 522nd-largest of the 80,743 networks we see originating IPv4, and the 4th-largest of 576 in Czechia. It is seen behind 40 upstream networks, most often AS6939 (Hurricane Electric LLC) and AS21320 (GEANT Vereniging), and in front of 19 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

26

IPv6 prefixes

1

IPv4 addresses

858k

IPv6 /64s

34.4B

Upstream graph

The networks AS2852 is seen behind, one and two hops out, drawn from real AS paths.

AS2852Toward the internet core
Upstream graph for AS2852: 12 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS2852CESNET z.s.p.o.This networkAS174Cogent Communicat…AS6939Hurricane Electri…AS21320GEANT VerenigingAS24482SG.GSAS60606PRO-ZETA a.s.AS1299Arelion (fka. Tel…AS151326DCConnect Communi…AS20130Depaul UniversityAS132337AxclusiveAS2603NORDUnetAS3356Lumen (Level 3)AS39392SH.cz s.r.o.

Networks observed one and two hops upstream of AS2852 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

258

adjacent networks

Upstreams
4016%
Peers
19977%
Downstreams
197%

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

Upstreams of AS2852
NetworkCountryRelationshipPathsVantage pts
AS6939Hurricane Electric LLCUSPeer1,03659
AS21320GEANT VerenigingNLPeer95825
AS174Cogent Communications, LLCUSPeer79832
AS60606PRO-ZETA a.s.CZPeer33918
AS24482SG.GSSGPeer2073
AS7713PT Telkom Indonesia TbkIDPeer1623
AS1853ACONETATPeer1413
AS6461Zayo BandwidthUSPeer1083
AS13030Init7 (Switzerland) Ltd.CHPeer1062
AS20965GEANT VerenigingNLPeer1022

Prefixes

All 27

The largest blocks AS2852 originates, widest first.

Largest prefixes originated by AS2852
PrefixAddressesVisibility
146.102.0.0/1665.5k76/76
147.32.0.0/1665.5k76/76
147.33.0.0/1665.5k76/76
147.228.0.0/1665.5k76/76
147.230.0.0/1665.5k76/76
147.231.0.0/1665.5k76/76
147.251.0.0/1665.5k76/76
158.194.0.0/1665.5k76/76
158.196.0.0/1665.5k76/76
160.216.0.0/1665.5k76/76

Routing health

How AS2852'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%27
  • Invalid0.0%0
  • No ROA0.0%0

Propagation

  • Globally propagated90% of full-feed peers or more100.0%27
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 26 prefixes

IPv6 — 1 prefixes

  • /2934.4B × /64100.0%1

Recent changes

Announcements that started or stopped since 12th Oct 2026.

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