Autonomous system
AS23631 KISNET - Sofu System, Inc
Unclassified ARIN
Summary
Sofu System
business japan software
AS23631 is operated by Sofu System, Inc.
What it's used for
- The address space carries corporate infrastructure, indicated by netnames
SoFu-System-CIDR-BLK-JPandNIIT-NET-CIDR-BLK-JP. - The AS announces 6144 IPv4 addresses across 2 prefixes and 1 IPv6 prefix, with only 1 observed neighbour, implying a small, self-contained business network rather than a transit or large access provider.
Notable
- Registrants for both IPv4 prefixes are listed as Japan Network Information Center, which is consistent with the Japanese registry allocation for the holder.
- The address inventory consists of two distinct IPv4 blocks and one IPv6 /32, representing a modest internal estate for a software development company based in Niigata, Japan.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
Recorded at 1 exchange in 1 country, largest first.
| Exchange | Location | Their address |
|---|---|---|
| Echigo Internet Exchange | Niigata, Japan | 58.84.254.20 |
Transit providers
1 upstream, 0 downstream and 2 adjacent networks observed; most-used upstreams first.
| AS | Network | Paths seen |
|---|---|---|
| AS18070 | Global Network Core Co.,Ltd. | 154 |
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-31, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 2 prefixes · 6.14K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| JP | Japan | 3 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS23631- Registry name
- KISNET
- Abuse contact
- hostmaster@nic.ad.jp
- Registered
- 2003-01-31
- Last changed
- 2003-05-28
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 3 with no ROA
- ROAs
- 0 authorising AS23631
- ASPA
- no ASPA record
- IRR
- 100% registered · 3 of 3 announcements
- Route objects
- 3 naming AS23631
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 447 networks and 1,843 prefixes, as published 2026-11-01. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere