asn.dev

Autonomous system

AS4721 JCN JCOM Co., Ltd.

Residential ARIN

IPv4 addresses 632K 54 prefixes
IPv6 prefixes 1 counted as prefixes, not addresses
Countries 1 mostly JP
Flagged prefixes 0 none

Summary

JCOM Co., Ltd. (former JCN)

Japan · AI-generated

isp legacy

JCN is one of the networks of JCOM Co., Ltd. (J:COM), Japan's largest cable

television and cable-broadband operator. It carries the name of Japan Cablenet

Limited (JCN), the operator J:COM absorbed in 2014.

What it's used for

  • Consumer broadband and cable-TV subscriber access on the former JCN footprint, now operated as part of J:COM.

Notable

  • This is eyeball address space: several hundred thousand IPv4 addresses handed out to residential cable-internet subscribers, so traffic to it is end users, not servers.
  • J:COM took over JCN's shares from KDDI in December 2013 and completed the merger on 1 April 2014; the ASN and its address blocks survived the corporate consolidation under the old handle.
  • J:COM runs more than one ASN — this one is specifically the ex-JCN network, not the group's primary AS.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.

Address space

Summary

Full explorer
CountryNamePrefixes
JPJapan55

Registry

Allocation record

via ARIN RDAP
Registry
ARIN
Handle
AS4721
Registry name
JCN
Last changed
2022-02-18
Status
active

Reputation

Classification and threat

Residential Fixed-line consumer ISP. Addresses here are homes.

No IC3 indicators Nothing from the FBI IC3 feed.

Threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.

Elsewhere

Cross-check