Reputation · trust score
A transparent 0–100 signal. Every entity starts at a neutral baseline of 65; threat-intel blocklists, exposure, reverse-DNS, routing and allocation each adjust it up or down. Higher is more trustworthy.
- Baseline (neutral) 65
- Trust score 65 / 100
Experimental · trust-vectors model v1.2.0 — a transparent heuristic, not a definitive verdict. How it works →
Network profile
Source: PeeringDB →Present at 2 internet exchanges: EPIX.Warszawa, Equinix Warsaw
Top CIDR ranges
| CIDR | IPs | PTR Density | Organization | Country | State | City |
|---|---|---|---|---|---|---|
| 91.207.184.0/23 | 512 |
98.4%
|
IT4 Polska Sp. z o.o. | PL | Mazovia | Wyszków |
| 217.28.134.0/24 | 256 |
0.0%
|
IT4 Polska Sp. z o.o. | PL | Mazovia | Wyszków |
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS203821 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.
| Prefix | Announcement samples | Last seen |
|---|---|---|
| 91.207.184.0/24 | 11,077 | 2026-07-31 01:37:46 |
| 91.207.185.0/24 | 10,993 | 2026-07-31 01:37:46 |
| 217.28.134.0/24 | 10,759 | 2026-07-31 01:37:46 |
| 91.207.184.216/32 | 244 | 2026-07-06 15:27:26 |
| 217.28.134.196/32 | 192 | 2026-07-27 14:06:12 |
| 217.28.134.211/32 | 111 | 2026-07-22 01:41:31 |
| 217.28.134.195/32 | 103 | 2026-07-25 02:09:51 |
| 217.28.134.207/32 | 102 | 2026-07-31 01:28:50 |
| 91.207.184.205/32 | 99 | 2026-07-27 16:38:41 |
| 217.28.134.212/32 | 79 | 2026-07-15 12:18:12 |
| 217.28.134.202/32 | 78 | 2026-07-08 22:04:28 |
| 91.207.184.195/32 | 62 | 2026-06-28 01:02:47 |
| 91.207.184.198/32 | 52 | 2026-07-28 16:17:23 |
| 91.207.184.196/32 | 49 | 2026-07-28 16:20:07 |
| 217.28.134.149/32 | 41 | 2026-07-27 00:25:12 |
| 91.207.184.202/32 | 40 | 2026-07-04 07:24:37 |
| 217.28.134.133/32 | 37 | 2026-07-27 09:12:22 |
| 91.207.184.193/32 | 31 | 2026-07-03 12:43:30 |
| 217.28.134.52/32 | 27 | 2026-07-03 22:30:28 |
| 217.28.134.145/32 | 26 | 2026-07-10 16:59:53 |
| 91.207.184.208/32 | 22 | 2026-07-29 12:08:53 |
| 91.207.184.199/32 | 21 | 2026-06-08 19:35:01 |
| 91.207.184.194/32 | 20 | 2026-05-27 16:04:02 |
| 217.28.134.214/32 | 18 | 2026-07-29 20:54:27 |
| 91.207.184.203/32 | 18 | 2026-07-27 20:22:29 |
| 91.207.184.185/32 | 15 | 2026-06-29 17:28:59 |
| 91.207.184.201/32 | 15 | 2026-06-13 11:58:23 |
| 217.28.134.146/32 | 14 | 2026-07-26 20:02:37 |
| 91.207.184.197/32 | 14 | 2026-07-26 00:57:25 |
| 91.207.184.222/32 | 14 | 2026-06-27 10:21:15 |
| 217.28.134.148/32 | 13 | 2026-07-27 09:55:52 |
| 217.28.134.130/32 | 13 | 2026-07-16 05:32:19 |
| 217.28.134.0/32 | 13 | 2026-07-02 20:44:32 |
| 217.28.134.192/32 | 11 | 2026-05-23 06:49:49 |
| 91.207.185.123/32 | 10 | 2026-05-22 12:06:21 |
| 91.207.184.0/32 | 6 | 2026-06-02 15:31:48 |
Frequently Asked Questions
What is AS203821?
AS203821 is an Autonomous System Number assigned to IT4 Polska Sp. z o.o.. An ASN identifies a network that controls a specific set of IP addresses and determines how traffic is routed across the internet via BGP (Border Gateway Protocol).
How many IP addresses does AS203821 announce?
AS203821 announces 768 IPv4 addresses distributed across 2 routed CIDR prefixes. The network is registered in Poland.
Who operates AS203821?
AS203821 is operated by IT4 Polska Sp. z o.o.. The organization is based in Poland. You can view all IP ranges and related ASNs on the organization page.
What country is AS203821 registered in?
AS203821 is registered in Poland. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
