asn.dev

Autonomous system

AS2511 CORE - Nippon Telegraph and Telephone Corporation

Unclassified APNIC

IPv4 addresses 41.73K 5 prefixes
IPv6 prefixes 0 counted as prefixes, not addresses
Countries 1 mostly JP
Exchanges 0 recorded by PCH
Upstreams 1 0 downstream
Flagged prefixes 0 none

Summary

Nippon Telegraph and Telephone Corporation (NTT)

Japan · AI-generated

enterprise legacy

This network (CORE) is registered to Nippon Telegraph and Telephone Corporation (NTT), Japan's largest telecommunications company.

What it's used for

  • An NTT-operated network. The CORE handle and modest address footprint suggest operational/backbone use rather than a distinct consumer ISP brand.

Notable

  • Operated by a major national telecom carrier. The low AS number reflects an early Japanese-internet allocation.

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

Full topology · Graph

Internet exchanges

No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.

Transit providers

1 upstream, 0 downstream and 1 adjacent networks observed; most-used upstreams first.

ASNetworkPaths seen
AS173Nippon Telegraph and Telephone Corporation292

Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-11-02, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.

Address space

Summary

Shape and geography

IPv4 5 prefixes · 41.73K addresses IPv6 0 prefixes

CountryNamePrefixes
JPJapan5

Registry

Allocation record

APNIC · via Atlas (registry + RDAP)
Registry
APNIC
Handle
AS2511
Registry name
CORE
Abuse contact
hostmaster@nic.ad.jp
Registered
2002-04-05
Last changed
2023-03-17
Allocation
allocated

Routing security

RPKI and IRR

Full detail
RPKI
100% valid · 5 valid, 0 with no ROA
ROAs
5 authorising AS2511
ASPA
no ASPA record
IRR
100% registered · 5 of 5 announcements
Route objects
10 naming AS2511

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: 448 networks and 1,851 prefixes, as published 2026-11-03. 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

Cross-check