AS9640 KRCERT-AS-KR Korea Internet Security Agency

AS9640 (KRCERT-AS-KR) is held by the Korea Internet & Security Agency (KISA), and the handle names its purpose: KrCERT/CC, the Korea Computer Emergency Response Team Coordination Center, South Korea's national CERT for the private sector. KISA sits under the Ministry of Science and ICT and also runs KRNIC, the registry for .kr and for Korea's IP address space.

What it's used for

The AS announces 6 IPv4 prefixes, 1,536 addresses, no IPv6, and has 2 observed BGP neighbours. Six /24s behind two upstreams is an end-site network: no customer cone, no transit role, nothing carrying third-party traffic. The neighbour count is the decisive signal — a network this size with hundreds of peers would be a carrier or a broker; with two, it buys connectivity and originates only its own space.

The composition of the six prefixes is the interesting part. Three of them — 192.5.90.0/24, 192.132.247.0/24 and 192.203.140.0/24 — sit in the old 192/8 class-C "swamp", space handed out in the earliest era of the registry system and rarely found outside organisations that are part of the internet's institutional furniture. The other three (218.37.128.0/24, 218.37.129.0/24, 180.222.220.0/24) are ordinary Korean assignments — the mix a body inherits when it holds pieces of the country's original registry infrastructure alongside later operational networks.

Notable

• KISA holds two low-numbered ASes here: AS9640 and [AS9642](https://asn.ipinfo.app/AS9642), under different handles. KISA is the product of a 2009 merger of three predecessor agencies, which likely explains more than one network record under one roof.
• The legacy class-C blocks show how far back this organisation's involvement in the network runs.