AS21309 CASAWEB-AS HERABIT S.p.A.

CASAWEB-AS HERABIT S.p.A. · registered in Italy

IPv4 addresses78,84812 prefixes · 0.003% of announced IPv4

Rank in Italy#33largest network in IT by IPv4 space, of 1,081 · 0.15% of IT

Rank worldwide#2,215of 79,396 networks with IPv4

IPv61 x /32 (65,536 x /48)1 prefixes

CountryItaly1,121 ASNs registered there

Open AS21309 in ASN lookup Look up an IP in this network (5.63.136.1) All networks in Italy

IPv4 prefixes

All 12 prefixes, in address order.

5.63.136.0/21
31.216.240.0/20
77.89.0.0/18
80.86.144.0/20
83.216.160.0/19
86.110.128.0/19
185.123.8.0/22
185.182.196.0/22
185.239.96.0/22
188.125.96.0/19
213.174.160.0/19
213.209.192.0/18

IPv6 prefixes

All 1 prefix.

2a03:c380::/32

Similar-sized networks in Italy

ASNNameIPv4 addresses

AS2594#30 ASN-CSI CSI Piemonte82,944

AS31638#31 ASN-LEPIDA Lepida S.c.p.A.80,384

AS12637#32 SEEWEB SEEWEB s.r.l.79,104

AS6882#34 RTRT-PEGASO Regione Toscana73,728

AS12551#35 AS-ENEL-IT ENEL S.p.A72,192

AS34606#36 ASN-BBBELL B.B.Bell SPA71,424

IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources