prefixkit Ask an engineerAsk RU

Autonomous systems

AS1221 Telstra Limited

Autonomous system AS1221 (Telstra Limited): 242 IPv4 networks (13,387,776 addresses) and 2 IPv6 networks, mostly in Australia. Prefix list for firewalls.

AS1221
Organisation
Telstra Limited
Countries (share of addresses)
Australia 99.9%
IPv4 addresses
13,387,776
IPv4 networks
242
IPv6 networks
2

IPv4 networks 242

Show 194 more

IPv6 networks 2

Prefix list for a firewall

Ready-made rules to allow or block the whole of AS1221.

What an autonomous system is

An autonomous system (AS) is the set of IP networks run by one organisation under a single routing policy. Providers, hosts and large companies announce their networks to the internet over BGP under their own AS number. With the number you can find all of an organisation’s addresses, for example to allow a service through a firewall or to block traffic from a network.

Network and country data come from DB-IP and are refreshed monthly. The country shows where addresses are used, not where the company is registered.