Autonomous system
AS43037 SEZNAM-
Hosting RIPE
Summary
Seznam.cz
portal search business czech
The AS handle SEZNAM- is held by Seznam.cz, a.s.
What it's used for
- The address space carries infrastructure for a major Czech web portal and search engine, with netnames
CZ-SEZNAM-20070507andCZ-SEZNAM-20140808registered to the company's IT department. - The AS announces 3072 IPv4 addresses across 2 prefixes and 42 IPv6 prefixes, while maintaining 111 observed neighbours; this ratio of modest address inventory to high peering density indicates a content and service provider rather than a transit carrier.
- Traffic from this AS consists of web and API endpoints serving the Seznam.cz portal, search engine, and associated digital services to users in the Czech Republic and Europe.
Notable
- Registrants for both announced IPv4 prefixes are Seznam.cz, a.s., matching the AS holder and confirming direct ownership of the address space.
- The inventory includes a large IPv6 allocation under the 2a02:598::/47 block, subdivided into multiple prefixes, reflecting the company's dual-stack infrastructure for its web services.
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 2 exchanges in 2 countries, largest first.
| Exchange | Location | Their address |
|---|---|---|
| DE-CIX Frankfurt | Frankfurt, Germany | 80.81.196.131 |
| NIX.CZ - Neutral Internet eXchange for the Czech Republic | Prague, Czech Republic | 91.210.16.194 |
Transit providers
21 upstream, 1 downstream and 36 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 2026-10-11, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 2 prefixes · 3.07K addresses IPv6 42 prefixes
| Country | Name | Prefixes |
|---|---|---|
| CZ | Czechia | 44 |
Registry
Allocation record
- Registry
- RIPE
- Handle
AS43037- Registry name
- SEZNAM-CZ
- Registrant
- Seznam.cz, a.s.
- Abuse contact
- abuse@seznam.cz
- Registered
- 2007-05-29
- Last changed
- 2017-11-15
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 100% valid · 12 valid, 0 with no ROA
- ROAs
- 13 authorising AS43037
- ASPA
- no ASPA record
- IRR
- 100% registered · 12 of 12 announcements
- Route objects
- 13 naming AS43037
Reputation
Classification and threat
Hosting Datacenter or cloud provider. Addresses are servers, not people.
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: 431 networks and 1,768 prefixes, as published 2026-10-12. 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