Autonomous system
AS2852 CESNET2
Education RIPE Educational/Research
Summary
CESNET (Czech Research and Education Network)
education research legacy
The Czech national research and education network (CESNET2), the production backbone operated by the CESNET association of universities and the Czech Academy of Sciences.
What it's used for
- Linking Czech universities, research institutes, and other member institutions to each other and to the international R&E internet.
Notable
- An institutional NREN, not a commercial ISP. Connected to the pan-European GÉANT network.
Interesting
- CESNET2 is the second-generation backbone name; the network dates to the early 1990s, matching its low RIPE-era AS number.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
Recorded at 3 exchanges in 3 countries, largest first.
| Exchange | Location | Their address |
|---|---|---|
| DE-CIX Frankfurt | Frankfurt, Germany | 80.81.194.214 |
| AMS-IX Amsterdam | Amsterdam, Netherlands | 80.249.209.106 |
| NIX.CZ - Neutral Internet eXchange for the Czech Republic | Prague, Czech Republic | 91.210.16.190 |
Transit providers
26 upstream, 19 downstream and 86 adjacent networks observed; most-used upstreams first.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-13, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 21 prefixes · 850K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| CZ | Czechia | 22 |
Registry
Allocation record
- Registry
- RIPE
- Handle
AS2852- Registry name
- CESNET2
- Registrant
- AS2852-MNT
- Abuse contact
- abuse@cesnet.cz
- Registered
- 2002-06-22
- Last changed
- 2026-09-13
- Allocation
- allocated
Declared
PeeringDB profile
- Name
- CESNET
- Network type
- Educational/Research
- Scope
- Europe
- Traffic ratio
- Balanced
- Peering policy
- Selective
- IRR as-set
AS2852:AS-CESNET-GOOGLE- Present at
- 3 exchanges
- Website
- https://www.cesnet.cz
PeeringDB records are maintained by the network operator and are not independently verified. Treat them as a statement of intent rather than of fact. For the observed and recorded view, see peering, which lists the exchanges Packet Clearing House has a port on file for.
Routing security
RPKI and IRR
- RPKI
- 100% valid · 27 valid, 0 with no ROA
- ROAs
- 31 authorising AS2852
- ASPA
- 9 declared providers
- IRR
- 100% registered · 27 of 27 announcements
- Route objects
- 55 naming AS2852
Reputation
Classification and threat
Education University, school or national research and education network.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 436 networks and 1,771 prefixes, as published 2026-10-13. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere