AS9622 KCT Kurashiki Cable TV

AS9622 (KCT) is held by Kurashiki Cable Television Co., Ltd., the largest cable operator in southern Okayama Prefecture, serving Kurashiki, Tamano, Soja, Hayashima and parts of Okayama City. It is a subsidiary of TOKAI Cable Network, part of TOKAI Holdings, and sells TV, fixed telephony and cable internet up to 10G.

What it's used for

A residential cable network with an unusually fragmented routing footprint: 47 announced IPv4 prefixes for only 74,752 addresses, plus one IPv6 /32 (2001:e90::/32). Many of those prefixes are more-specifics announced alongside their own covering aggregate (124.47.64.0/18 together with 124.47.64.0/20, 203.76.64.0/19 with 203.76.64.0/20, 211.125.96.0/19 with both its /20 halves), so the real address count is far smaller than the prefix count suggests. The reverse DNS is the most self-documenting in this batch: PTRs resolve under kct.ad.jp with labels cidr1 through cidr11, one per block the operator has been granted, and one block is explicitly tagged dynamic (211-125-96-5.dynamic.cidr1.kct.ad.jp). That is an eyeball operator numbering its own address history. The 22 observed BGP neighbours sit at the level of a regional ISP with redundant upstreams and domestic peering.

Notable

• The cidrN rDNS scheme means you can read the operator's allocation order straight out of a hostname.
• Deaggregation on this scale (47 prefixes for 74k addresses) is the operator carrying more-specifics for traffic engineering rather than a sign of scattered or brokered inventory. The blocks are all consistently KCT-named.