Data as of Nov 13, 2026
81.31.45.0/27
No anonymizer space · no proxy exits in 30 daysMasterDC s.r.o.
Registrations in this block
The registry's network records over this block, widest first, each under its parent.
| Range | Addresses | Netname | Holder | Type | Created | Abuse contact |
|---|---|---|---|---|---|---|
| 81.31.32.0/20 | 4,096 | CZ-MASTER-20020528 | MasterDC s.r.o. (ORG-MIS2-RIPE) · CZ | ALLOCATED PA | May 28, 2002 | abuse@ |
| └ 81.31.45.0/27 | 32 | SYSTEM4U-2-MAI-CZ | system4u s.r.o. | ASSIGNED PA | Apr 9, 2014 | abuse@ via CZ-MASTER-20020528 |
A contact marked “via” is the registry's: the record names none of its own, so the registry hands down its parent's.
Network & registry
Announced by
Covering announcement 81.31.32.0/20
- Prefix
- 81.31.32.0/20
- Announced by
- AS24971 MasterDC s.r.o.
- Type
- Hosting
- RPKI
- RPKI valid
- Netname
- CZ-MASTER-20020528
- Registrant
- MasterDC s.r.o.
- RIR
- RIPE NCC
Origin network
AS24971
CZ
- Name
- MasterDC s.r.o.
- Type
- Hosting
- Registered
- Jun 11, 2002
- Domain
- master.cz
- Website
- www.master.cz
- Industry
- Hosting and Cloud Provider
- Spamhaus ASN-DROP
- not listed
Routing timeline
Who has announced 81.31.32.0/20
81.31.32.0/20
Routing history
- Pattern
- Stable
- First seen
- May 2005
- Current origin since
- May 2005 · 22 yr
- Origin networks
- 1
RPKI
Route origin authorizations
| ROA prefix | ASN | Max len | Anchor | Verdict |
|---|---|---|---|---|
| 81.31.32.0/20 | AS24971 | /20 | RIPE | RPKI valid |
IRR
Route objects on 81.31.32.0/20
| Origin | Registry | Description | Maintainer | Modified |
|---|---|---|---|---|
| AS24971 | RIPE | MASTER-NET-1 | MASTER-MNT | Jun 17, 2002 |
Whois
Registration for this announcement
- Range
- 81.
31. 32. 0/ 20 - Netname
- CZ-MASTER-20020528
- Registrant
- MasterDC s.r.o.
- Registrant country
- CZ
- Organization
- MasterDC s.r.o. (ORG-MIS2-RIPE)
- Org country
- CZ
- Type
- ALLOCATED PA
- Created
- May 28, 2002
- Updated
- Jan 17, 2017
- Maintainer
- RIPE-NCC-HM-MNT
- RIR
- RIPE NCC
- Country
- CZ
- Delegated
- May 28, 2002
- Status
- assigned
Report abuse
Abuse contact
- abuse@
master. cz - Name
- MasterDC contact
- Handle
- MAIC-RIPE