AS253

AS253 is a legacy autonomous system number registered under ARIN to NTT America, Inc., the US subsidiary of NTT Ltd (part of the Tokyo-headquartered NTT Group). It carries the ARIN handle NTTA-253 and resolves to NTT America's Greenwood Village, Colorado registration address. The key triage point for AS253 is that it is operationally dormant: every routing source consulted (RIPEstat, CAIDA AS Rank, bgp.tools, IPinfo) agrees it currently announces zero IPv4 and zero IPv6 prefixes, has zero visible BGP peers, zero upstreams, and no IXP memberships. RIPEstat routing history shows the ASN was active in the past — first prefix seen 2007-08-23 (204.0.51.0/24) and last prefix seen 2020-12-03 (103.111.14.0/24) — but it has been dark in the global routing table since late 2020. Its CAIDA AS rank of 79,459 sits near the bottom of the global ranking, with a singleton customer cone (the ASN itself, 0 prefixes, 0 addresses). NTT America's active commercial Tier-1 backbone — the NTT DATA Global IP Network (GIN) — runs under AS2914, not AS253; the published open peering policy and RPKI-mandatory routing requirements at gin.ntt.net apply to AS2914. PeeringDB returns 404 for /asn/253, confirming AS253 has no PeeringDB record of its own. RPKI posture cannot be assessed for AS253 because there are no active originations and therefore no ROAs to validate. No notable public abuse signal was found as of June 2026 — not in Spamhaus ASN-DROP, CleanTalk, AbuseIPDB, CIRCL BGP Ranking, FireHOL, or NANOG archives — consistent with a clean, dormant ASN held by a respected Tier-1 operator.

Operator

NTT America, Inc. (US subsidiary of NTT Ltd / NTT Group; ARIN handle NTTA-253) [Confirmed] — ARIN RDAP autnum/253, ipinfo.io/AS253

Country / RIR

US, ARIN [Confirmed] — ARIN RDAP autnum/253

Allocated

2000-04-12 (ARIN RDAP autnum top-level registration event, NOT a contact-record date — entity-level 2005-12-02 dates are POC records, not the ASN allocation); last changed 2012-03-02 [Confirmed] — ARIN RDAP autnum top-level events

Org status

active corporate entity — NTT America, Inc. is one of NTT Ltd's direct subsidiaries; AS253 itself is ARIN-registered and status-active in the registry but carries no active prefixes [Confirmed] — ARIN RDAP, services.global.ntt subsidiaries page

Contacts

abuse@ntt.net (NAAC-ARIN); ce-support@gin.ntt.net (NASC-ARIN, NOC); peering@ntt.net (PEERI-ARIN); +1-877-688-6625; registration address 8300 E Maplewood Ave., Suite 400, Greenwood Village, CO 80111 [Confirmed] — ARIN RDAP autnum/253

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-20 — not in Spamhaus ASN-DROP, CleanTalk, AbuseIPDB, CIRCL BGP Ranking, FireHOL, or NANOG archives; dormant ASN under a respected Tier-1 operator

Network & routing

Network type

global Tier-1 IP carrier (NTT America); AS253 is legacy/inactive — NTT America's active backbone runs under AS2914 (NTT DATA Global IP Network) [Confirmed] — gin.ntt.net/about, bgp.tools/as/253, ARIN RDAP

Size

dormant — 0 IPv4 prefixes / 0 IPv4 addresses and 0 IPv6 prefixes; customer cone = 1 ASN (itself), 0 prefixes, 0 addresses — RIPEstat routing-status / CAIDA AS Rank (2026-06)

Routing/peering

NOT announced — 0 RIS peers seeing it (0/327 v4, 0/324 v6); CAIDA degree total 0 (customer 0, peer 0, provider 0); no upstreams or peers visible [Confirmed]. Historically active: first prefix 204.0.51.0/24 (2007-08-23), last prefix 103.111.14.0/24 (2020-12-03) [Confirmed] — RIPEstat routing-status. NTT's published open peering policy applies to AS2914, not AS253

[Likely for AS2914 policy] — gin.ntt.net/support-center/policies-procedures/routing/

RPKI

not assessable — AS253 announces no prefixes, so there are no ROAs to validate [Unknown] — A3 routing (RPKI validation skipped, no active prefix)

Notable usage

AS253 (NTTA-253) is an early/legacy NTT America ASN, dark in global routing since late 2020; active NTT America infrastructure runs under AS2914 (Tier-1 GIN backbone) [Likely] — bgp.tools/as/253, ipinfo.io/AS253, gin.ntt.net

Related ASNs

AS2914 (NTT America's active Tier-1 Global IP Network) [Confirmed]; NTT America holds additional legacy ASNs (e.g. AS262, AS275, AS3150, AS3938, AS3949, AS11158) [Likely per third-party DBs]

Analyst note

Encountered as a dormant legacy ASN registered to a major Tier-1 operator; WHOIS resolves to NTT America, but live routing is under AS2914, not AS253. Clean, inactive ASN.