AS7521 — MFEED INTERNET MULTIFEED CO.

Network type: residential

AS7521 announces 8 IPv4 prefixes covering 4,864 addresses and 10 IPv6 prefixes.

About this network

MFEED — INTERNET MULTIFEED CO., founded in 1997 as a joint venture of NTT and IIJ. It operates JPNAP, one of Japan's main internet exchanges, along with data centre, IPv6 transition (transix) and public time services.

What it's used for

• Running the JPNAP exchange fabrics in Tokyo and Osaka, where Japanese ISPs and content networks peer.
• Multifeed's own service and management infrastructure: the rDNS on its space is operational, not customer-facing — firewalls, VPN concentrators and servers under mfeed.ad.jp.
• Serving ntp.jst.mfeed.ad.jp, the widely used public NTP service that distributes Japan Standard Time from NICT's clocks.

Notable

• Only ~4,900 IPv4 addresses, which badly understates it. Like any exchange operator, the traffic it handles crosses peering LANs that are not globally routed, so none of it shows up in this AS's prefix count.
• Infrastructure with no honest commercial "kind": it is not an eyeball ISP, a hosting provider or a transit seller. Compare AS7527 (JPIX), Japan's other major exchange operator.

Interesting

• The public NTP service means a very large share of clocks in Japan, on consumer routers and servers alike, are ultimately steered by hosts in this small AS.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 115.69.237.0/24
• 210.173.160.0/21
• 210.173.168.0/24
• 210.173.170.0/24
• 210.173.172.0/24
• 210.173.178.0/24
• 210.173.180.0/22
• 210.173.186.0/23
• 2001:3a0::/32
• 2001:3a0:f008::/45
• 2001:3a0:f010::/44
• 2001:3a0:f020::/43
• 2001:3a0:f040::/42
• 2001:3a0:f080::/41
• 2001:3a0:f100::/40
• 2001:3a0:f200::/39
• 2001:3a0:f400::/38
• 2001:3a0:f800::/37

Upstream networks

• AS55391 INTERNET MULTIFEED CO.

Downstream networks

• AS63802 Nippon Telegraph and Telephone East Corporation
• AS4697 Nippon Telegraph and Telephone Corporation
• AS38644 INTERNET MULTIFEED CO.
• AS131079 INTERNET MULTIFEED CO.
• AS200070 CZ.NIC, z.s.p.o.
• AS173 Nippon Telegraph and Telephone Corporation

Adjacent networks

• AS55391 INTERNET MULTIFEED CO.
• AS63802 Nippon Telegraph and Telephone East Corporation
• AS4697 Nippon Telegraph and Telephone Corporation
• AS38644 INTERNET MULTIFEED CO.
• AS131079 INTERNET MULTIFEED CO.
• AS200070 CZ.NIC, z.s.p.o.
• AS173 Nippon Telegraph and Telephone Corporation