Autonomous system
AS24971 MASTER-AS Czech Republic www.master.cz
Hosting RIPE
Summary
MasterDC
hosting datacenter czech business
The AS handle MASTER-AS is operated by MasterDC s.r.o., a Czech data center and hosting provider.
What it's used for
- The address space carries data center and virtualization infrastructure, evidenced by reverse DNS entries such as
static.masterinter.net,network.master-c2.virtualmaster.cz, and internal rack identifiers likevl25.sl527s.r1-8.dc1.4d.prg.masterinter.net. - The AS announces 58,112 IPv4 addresses across 31 prefixes and 26 IPv6 prefixes, while maintaining 41 observed routing neighbours. This ratio of substantial address inventory to a moderate number of peers indicates a hosting and business access network rather than a transit provider.
Notable
- Registrants for the majority of the largest prefixes, including
77.93.192.0/19and83.167.224.0/19, are listed as MasterDC s.r.o., aligning with the AS holder. However, some blocks are registered to third parties, such asvpsFree.cz, z.s.for37.205.8.0/21andW HOSTING, s.r.o.for91.226.216.0/22, suggesting leased space or customer allocations. - The inventory consists of a mix of large /19 and /20 blocks alongside numerous smaller /22 and /24 prefixes, reflecting a segmented corporate estate with distinct subnets for different services or customer groups.
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 1 country, largest first.
| Exchange | Location | Their address |
|---|---|---|
| Peering.cz | Prague, Czech Republic | 185.0.20.14 |
| NIX.CZ - Neutral Internet eXchange for the Czech Republic | Prague, Czech Republic | 91.210.16.85 |
Transit providers
9 upstream, 8 downstream and 30 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 2026-10-10, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 31 prefixes · 58.11K addresses IPv6 26 prefixes
| Country | Name | Prefixes |
|---|---|---|
| CZ | Czechia | 57 |
Registry
Allocation record
- Registry
- RIPE
- Handle
AS24971- Registry name
- MASTER-AS
- Registrant
- MASTER-MNT
- Abuse contact
- abuse@master.cz
- Registered
- 2002-06-11
- Last changed
- 2026-09-22
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 98% valid · 45 valid, 1 with no ROA
- ROAs
- 46 authorising AS24971
- ASPA
- 2 declared providers
- IRR
- 100% registered · 46 of 46 announcements
- Route objects
- 54 naming AS24971
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 1,775 prefixes, as published 2026-10-11. 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