AS18403 is FPT Telecom’s network.
AS18403 belongs to FPT Telecom Company. DB-IP Lite attributes 1,422,080 IPv4 addresses in 21 ranges and 1 IPv6 ranges to it, all or nearly all of the IPv4 space in Vietnam. The number is registered with APNIC in Vietnam on 3 Jan 2003.
Does it publish a geofeed?
Not for the range we sampled (42.112.0.0 – 42.119.255.255): its registry record, and the record above it, link no RFC 8805 geofeed (checked 2 Nov 2026). Without one, location databases have to estimate where these addresses are used, which is a common reason customers of FPT Telecom see the wrong city. Customers can ask FPT Telecom to publish one; the evidence report drafts that request.
Shared addresses (CGNAT)
FPT Telecom hasn’t been documented as using carrier-grade NAT in a source we could check. To see whether your own connection is behind it, compare your router’s address on the CGNAT check.
IPv6
DB-IP lists 1 IPv6 ranges for AS18403, so customers can get IPv6 addresses, which databases place separately from IPv4.
Where its IPv4 space is used, according to DB-IP
Share of the network’s IPv4 addresses by DB-IP Country Lite. IP Geolocation by DB-IP.
IP ranges
IP Geolocation by DB-IP, ASN Lite, CC BY 4.0.
Using an address from this network? See which sources agree on where it is.
Sources
- DB-IP IP to ASN Lite (CC BY 4.0) · checked 3 Nov 2026
- NRO RIR delegated-extended statistics · checked 5 Nov 2026