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Autonomous systems

AS2856 British Telecommunications PLC

Autonomous system AS2856 (British Telecommunications PLC): 526 IPv4 networks (13,845,504 addresses) and 5 IPv6 networks, mostly in United Kingdom. Prefix list for firewalls.

AS2856
Organisation
British Telecommunications PLC
Countries (share of addresses)
United Kingdom 99.9% United States 0.1%
IPv4 addresses
13,845,504
IPv4 networks
526
IPv6 networks
5

IPv4 networks 526

Show 478 more

IPv6 networks 5

Prefix list for a firewall

Ready-made rules to allow or block the whole of AS2856.

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.