| Rank | AS number | Organization | IPv4 addresses |
|---|---|---|---|
| 1 | AS3269 | ASN-IBSNAZ Telecom Italia S.p.A. | 19,828,223 |
| 2 | AS1267 | ASN-WINDTRE WIND TRE S.P.A. | 7,396,352 |
| 3 | AS30722 | VODAFONE-IT-ASN Fastweb SpA | 5,575,936 |
| 4 | AS12874 | FASTWEB Fastweb SpA | 3,562,752 |
| 5 | AS137 | ASGARR Consortium GARR | 2,745,344 |
| 6 | AS16232 | ASN-TIM Telecom Italia S.p.A. | 1,777,664 |
| 7 | AS8968 | BT-Italia RETELIT-X S.R.L. | 821,504 |
| 8 | AS3302 | AS-RETELIT-IRIDEOS Retelit Digital Services S.p.A. | 617,984 |
| 9 | AS24608 | WINDTRE-AS WIND TRE S.P.A. | 549,888 |
| 10 | AS8612 | TISCALI-IT Smeraldo S.p.A. | 525,055 |
| 11 | AS12663 | VODAFONE-GROUP Fastweb SpA | 361,472 |
| 12 | AS35612 | NGI-AS EOLO S.p.A. | 361,472 |
| 13 | AS210278 | SKYIT-BB Sky Italia srl | 328,704 |
| 14 | AS31034 | ARUBA-ASN Aruba S.p.A. | 282,624 |
| 15 | AS6762 | SEABONE-NET TELECOM ITALIA SPARKLE S.p.A. | 280,832 |
| 16 | AS20746 | ASN-IDC Telecom Italia S.p.A. | 215,552 |
| 17 | AS213677 | FIBERCOP Fibercop S.p.A. | 197,632 |
| 18 | AS29286 | SKYLOGIC-AS SKYLOGIC S.P.A. | 164,864 |
| 19 | AS3313 | INET-AS RETELIT-X S.R.L. | 158,208 |
| 20 | AS210218 | OpenFiber-Italy Open Fiber S.P.A. | 147,712 |
| 21 | AS198471 | OPNET-AS Opnet Srl | 142,336 |
| 22 | AS30848 | IT-TWT-AS UNIDATA S.p.A. | 122,880 |
| 23 | AS31263 | MYNET-AS MYNET S.R.L. | 101,888 |
| 24 | AS12797 | ASN-ATLANET RETELIT-X S.R.L. | 98,816 |
| 25 | AS21056 | ASN-WELCOMEITALIA Vianova S.p.A | 98,816 |
| 26 | AS5394 | Unidata UNIDATA S.p.A. | 91,904 |
This product includes GeoLite2 data created by MaxMind, available from https://www.maxmind.com.