AS9781 GCS-AS-KR GREEN CABLE TELEVISION STATION

AS9781 (GCS-AS-KR) is held by Green Cable Television Station, a cable television and broadband system operator based in Dalseo-gu, Daegu, in south-eastern South Korea. Despite the broadcast-sounding name, the AS is a working access ISP: Korean cable SOs have delivered internet over their HFC plant for decades, and the routing evidence matches that role.

What it's used for

Residential and small-business broadband in the operator's franchise area. RIS sees 65 IPv4 prefixes carrying 106,496 addresses against only 4 observed BGP neighbours. That ratio is the tell. A hundred thousand addresses is a substantial pool, but a wholesale carrier holding that much space would peer with hundreds of networks; four adjacencies means the traffic is going one way, out to a small number of national upstreams, and the addresses are being consumed by the operator's own subscribers. Publicly reported upstreams are the major Korean carriers, which is exactly the shape of a regional cable ISP buying transit rather than selling it.

Notable

• The address space is deeply fragmented for a network of this size: 65 announcements built from a couple of /18s in 121.55.0.0 and 114.199.0.0, a stack of /19s and /20s, and many smaller pieces, several of them more-specifics of each other.
• No IPv6 is announced, which leaves subscribers on IPv4 only.
• The operator is a regional player tied to Daegu, not one of the nationwide Korean broadband brands.