Autonomous system
AS59959 SFERIA
Residential APNIC
Summary
SferiaNET
isp residential czech cable
The AS handle SFERIA is held by SferiaNET.cz s.r.o.
What it's used for
- The address space carries residential and business internet access, evidenced by reverse DNS entries such as
0-157-3-185.advnet.czand255-93-35-193.advnet.cz. - The network announces 4,096 IPv4 addresses across 4 prefixes and 1 IPv6 prefix, while maintaining 27 observed neighbours, indicating a role as a regional access provider with moderate peering.
- Traffic from this AS consists of subscriber eyeballs for cable and DSL services in the Czech Republic, as SferiaNET operates as a local ISP providing reliable internet and digital services.
Notable
- All four IPv4 prefixes are registered to SferiaNET.cz s.r.o. with netnames
CZ-SFERIA-20120920,CZ-SFERIA-20160413,CZ-SFERIA-20180126, andCZ-SFERIA-20180911, confirming consistent ownership. - The address inventory is composed of four /22 blocks, representing a finely subdivided corporate estate typical of a regional ISP managing distinct customer segments or geographic areas.
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 | 185.0.20.143 |
| NIX.CZ - Neutral Internet eXchange for the Czech Republic | Prague, Czech Republic | 91.210.16.174 |
Transit providers
7 upstream, 0 downstream and 13 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 4 prefixes · 4.10K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| CZ | Czechia | 5 |
Registry
Allocation record
- Registry
- APNIC
- Handle
AS59959- Registry name
- SFERIA
- Registrant
- cz-sferia-MK-mnt
- Abuse contact
- abuse@sferia.cz
- Registered
- 2018-01-26
- Last changed
- 2023-05-22
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 40% valid · 2 valid, 3 with no ROA
- ROAs
- 2 authorising AS59959
- ASPA
- no ASPA record
- IRR
- 100% registered · 5 of 5 announcements
- Route objects
- 5 naming AS59959
Reputation
Classification and threat
Residential Fixed-line consumer ISP. Addresses here are homes.
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