Autonomous system
AS43542 OPTONET-AS
Unclassified RIPE
Summary
OptoNet Communication
isp hosting czech
The AS handle OPTONET-AS is held by OptoNet Communication, spol. s.r.o.
What it's used for
- The address space carries residential and business internet access, evidenced by reverse DNS entries such as
client-254-vynet.net,ip.143.126.user.trestsko.net, andhost-141-64.ktvmb.cz. - The network announces 7,936 IPv4 addresses across 5 prefixes and 1 IPv6 prefix, with 27 observed neighbours, indicating a regional access provider with moderate peering.
- Traffic from this AS consists of subscriber eyeballs, IP telephony, IPTV, and hosted web services, consistent with the operator's provision of internet connectivity, server rental, and cloud technologies.
Notable
- All registrants for the announced prefixes are OptoNet Communication, spol. s.r.o., matching the AS holder.
- The address inventory is concentrated in the 78.156.128.0/21 block, with smaller subdivisions for specific customer segments or 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 1 exchange in 1 country, largest first.
| Exchange | Location | Their address |
|---|---|---|
| NIX.CZ - Neutral Internet eXchange for the Czech Republic | Prague, Czech Republic | 91.210.17.48 |
Transit providers
7 upstream, 4 downstream and 19 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 5 prefixes · 7.94K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| CZ | Czechia | 6 |
Registry
Allocation record
- Registry
- RIPE
- Handle
AS43542- Registry name
- OptoNet-AS
- Registrant
- MNT-OPTONET
- Abuse contact
- abuse@optonet.cz
- Registered
- 2007-08-20
- Last changed
- 2026-03-16
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 100% valid · 2 valid, 0 with no ROA
- ROAs
- 3 authorising AS43542
- ASPA
- no ASPA record
- IRR
- 100% registered · 2 of 2 announcements
- Route objects
- 3 naming AS43542
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
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