asn.dev

Autonomous system

AS203821 IT4-POLSKA

Unclassified RIPE

IPv4 addresses 768 2 prefixes
IPv6 prefixes 0 counted as prefixes, not addresses
Countries 1 mostly PL
Exchanges 1 recorded by PCH
Upstreams 1 0 downstream
Flagged prefixes 0 none

Summary

IT4 Polska

Poland · AI-generated

isp residential regional cable

The AS handle IT4-POLSKA is held by IT4 Polska Sp. z o.o.

What it's used for

  • The address space carries residential and business connectivity, evidenced by reverse DNS entries such as ip-91-207-184-128.it4polska.com and netnames it4polska-pl and PL-ENFORMATEL-20220413.
  • The network announces 768 IPv4 addresses across 2 prefixes and maintains 4 observed neighbours, a ratio consistent with a regional access provider rather than a transit hub.
  • Traffic from this AS consists of subscriber eyeballs and local business endpoints served by a regional cable and DSL operator.

Notable

  • Registrants include Sylwester Harasim for the it4polska-pl netname and Enformatel Sp. z o.o. for the PL-ENFORMATEL-20220413 netname, indicating a mix of direct and potentially leased or partner-managed address space.
  • The address inventory is small and concentrated in two blocks, one of which is a /23 and the other a /24, typical of a niche regional ISP.

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

Full topology · Graph

Internet exchanges

Recorded at 1 exchange in 1 country, largest first.

ExchangeLocationTheir address
Equinix Internet Exchange WarsawWarsaw, Poland195.182.219.47

Transit providers

1 upstream, 0 downstream and 1 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS51465M3.NET Sp. zoo177

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-28, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.

Address space

Summary

Shape and geography

IPv4 2 prefixes · 768 addresses IPv6 0 prefixes

CountryNamePrefixes
PLPoland2

Registry

Allocation record

RIPE · via Atlas (registry + RDAP)
Registry
RIPE
Handle
AS203821
Registry name
IT4-POLSKA
Registrant
DGNET-MNT
Abuse contact
biuro@it4polska.pl
Registered
2015-10-23
Last changed
2020-11-16
Allocation
allocated

Routing security

RPKI and IRR

Full detail
RPKI
0% valid · 0 valid, 3 with no ROA
ROAs
0 authorising AS203821
ASPA
no ASPA record
IRR
100% registered · 3 of 3 announcements
Route objects
4 naming AS203821

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: 448 networks and 1,851 prefixes, as published 2026-10-29. 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

Cross-check