prefixkit Ask an engineerAsk RU

Autonomous systems

AS209554 ISIF OU

Autonomous system AS209554 (ISIF OU): 13 IPv4 networks (6,912 addresses) and 19 IPv6 networks, mostly in Hong Kong SAR China. Prefix list for firewalls.

AS209554
Organisation
ISIF OU
Countries (share of addresses)
Hong Kong SAR China 77.6% Japan 11.1% Singapore 7.4% United States 3.7%
IPv4 addresses
6,912
IPv4 networks
13
IPv6 networks
19

IPv4 networks 13

IPv6 networks 19

Prefix list for a firewall

Ready-made rules to allow or block the whole of AS209554.

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.