AS9601 SHIBATA Niigata Communication Service

AS9601 (SHIBATA) is held by Niigata Communication Service Co., Ltd. (株式会社新潟通信サービス), a regional ISP based in Shibata City, Niigata Prefecture. It operates the Internet Shibata and BB.Niigata connectivity brands and runs its own fibre network across the prefecture, serving both residential subscribers and local businesses.

What it's used for

This is a small regional access network. It announces 7 IPv4 prefixes for 27,648 addresses, the largest being two /19s (114.134.32.0/19, 211.12.192.0/19), plus three IPv6 blocks carved out of 2402:a800::/33. The reverse DNS is uniformly per-address subscriber naming, with fi005.p32, fi1005.i208 and n5.m48 style hostnames indexed by the position of the address inside its parent block. That mechanical, generated-per-line pattern is exactly what an access ISP produces for its PPPoE and fixed-line pools, and it appears across every announced block, not just one. The 15 observed BGP neighbours sit at the level a small provider needs for redundant upstreams and a couple of domestic peering sessions, not the hundreds a transit network would carry.

Notable

• The SHIBATA handle is a place name, not a person or a brand: Shibata City is where the company is headquartered and where its ISP service Internet Shibata takes its name from.
• The IPv6 deployment is unusual for a network this size. Three nested blocks (/33, /34, /35) from a single 2402:a800:: parent suggest the address plan is subdivided by region or service rather than announced as one aggregate.