AS275

AS275 is an autonomous system number registered under ARIN to NTT America, Inc., the U.S. arm of the NTT group (the publicly listed Japanese carrier Nippon Telegraph and Telephone Corporation, TSE: 9432). In routing terms it is a small stub AS rather than a backbone: it originates exactly two prefixes — one IPv4 block, 204.141.84.0/22 (1,024 addresses), and one IPv6 block, 2001:418:144d::/48 — and carries no transit. Its single visible BGP relationship is to AS2914, NTT's Tier 1 Global IP Network (GIN), which serves as AS275's sole upstream and only peer. Both originated prefixes are ROA-signed and IRR-valid, giving AS275 a clean RPKI posture. The triage point is that AS275 is a narrow internal sub-ASN inside the much larger NTT America footprint: NTT's primary global operations and peering run under AS2914, and AS275 itself sees very limited routing activity (bgp.he.net records an average AS path length of about 4.23 across roughly 722 IPv4 and 660 IPv6 observed paths). No notable public abuse signal was found as of 2026-06-21 — AS275 is absent from Spamhaus ASN-DROP, the ipapi.is most-abusive-ASN list, the brianhama bad-asn-list, and NANOG security/abuse threads (incidents naming NTT reference AS2914, not AS275). The ARIN-registered abuse contact is abuse@ntt.net. IPinfo tags at least one IP in the block as a VPN endpoint, and infrastructure has been observed in Frankfurt despite the U.S. registration.

Operator

NTT America, Inc. (U.S. subsidiary of the NTT group; ARIN ASN name NTTA-275, org handle NTTAM-1) [Confirmed] — ARIN RDAP autnum/275, ipinfo.io/AS275

Country / RIR

US, ARIN [Confirmed] — ARIN RDAP autnum/275, bgp.he.net/AS275

Allocated

2000-03-29 (ARIN autnum top-level registration event; NOT an IEEE date — IEEE publishes no ASN dates); last changed 2012-03-02 [Confirmed] — ARIN RDAP autnum top-level events[] (A3 isolated the autnum object via fetch-canonical; entity-level 2005-12-02 dates are contact-record dates, not the allocation)

Org status

commercial subsidiary — NTT America, Inc. is part of the NTT group (Nippon Telegraph and Telephone Corp., TSE: 9432), incorporated in New York (1996) [Confirmed] — group.ntt corporate overview, ARIN RDAP autnum/275

Contacts

abuse@ntt.net (NAAC-ARIN); ce-support@gin.ntt.net (NOC, NASC-ARIN); peering@ntt.net (PEERI-ARIN); tel +1-877-688-6625; registered address 8300 E Maplewood Ave., Suite 400, Greenwood Village, CO 80111 [Confirmed] — ARIN RDAP autnum/275

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal as of 2026-06-21 — absent from Spamhaus ASN-DROP, ipapi.is most-abusive-ASN top list, brianhama bad-asn-list, and NANOG abuse/hijack threads (NTT incidents reference AS2914, not AS275)

Network & routing

Network type

stub AS — single-homed to AS2914, no transit; originates only its own prefixes [Confirmed] — ipinfo.io/AS275, bgp.he.net/AS275

Size

1 IPv4 prefix (204.141.84.0/22, 1,024 addresses) + 1 IPv6 prefix (2001:418:144d::/48); IPv6 host count not published [Confirmed for prefixes; Unknown for IPv6 host estimate] — bgp.he.net/AS275

Routing/peering

AS2914 (NTT GIN) is the sole upstream and only observed BGP peer for both IPv4 and IPv6; ~722 IPv4 / ~660 IPv6 AS paths observed; average AS path length ~4.23 [Confirmed] — bgp.he.net/AS275. No AS275-specific peering policy is published; the parent AS2914/GIN runs a Restrictive policy (peering@ntt.net)

[Confirmed for AS2914 policy] — peeringdb.com/net/1045, gin.ntt.net routing policy

RPKI

Valid — both originated prefixes are ROA-signed and IRR-valid [Confirmed] — bgp.he.net/AS275. (bgp.he.net also flags a bogon announcement; the /22 itself is a legitimate ARIN block, so this likely reflects a stale/edge-case filter classification) [Likely] — bgp.he.net/AS275

Notable usage

narrow internal sub-ASN within NTT America; announces a /22 + a /48 with no transit. IPinfo tags at least one IP as a VPN endpoint and observes infrastructure in Frankfurt despite the US registration [Confirmed] — ipinfo.io/AS275, bgp.he.net/AS275

Related ASNs

AS2914 (NTT's Tier 1 GIN backbone) — AS275's sole upstream/peer and the operator of NTT's primary global routing [Confirmed] — ipinfo.io/AS275, bgp.he.net/AS275

Analyst note

AS rank and customer-cone size could not be determined from available sources (CAIDA/bgp.tools data unavailable; bgp.tools returned HTTP 500). AS275 is a clean, lightly-routed stub under NTT America; treat AS2914 as the operationally significant NTT ASN.