subnet.im

AS18403FPT Telecom Company

VietnamRegistryAPNICTypeEyeball

As of 10th November 2026, AS18403 (FPT Telecom Company), an access network registered in Vietnam with APNIC, originates 4,771 IPv4 prefixes covering 6.2M addresses and 3,752 IPv6 prefixes. By IPv4 address space that makes it the 117th-largest of the 80,723 networks we see originating IPv4, and the 3rd-largest of 537 in Vietnam. It is seen behind 77 upstream networks, most often AS1299 (Arelion (fka. Telia Carrier)) and AS3356 (Lumen (Level 3)), and in front of 252 downstream networks. Over 99% of its announcements have a valid RPKI ROA; 26 are RPKI-invalid. 11% of its routes reach at least 90% of full-feed peers, and 1 prefix is also originated by another network.

At a glance

IPv4 prefixes

4,771

IPv6 prefixes

3,752

IPv4 addresses

6.2M

IPv6 /64s

42.2B

Upstream graph

The networks AS18403 is seen behind, one and two hops out, drawn from real AS paths.

AS18403Toward the internet core
Upstream graph for AS18403: 12 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS18403FPT Telecom Compa…This networkAS1299Arelion (fka. Tel…AS3356Lumen (Level 3)AS4637Telstra Internati…AS6939Hurricane Electri…AS49544i3D.net B.VAS13030Init7 (Switzerlan…AS3549Lumen (fka. Globa…AS16552Tiggee LLCAS32590Valve CorporationAS2914NTT America, Inc.AS20130Depaul UniversityAS132337Axclusive

Networks observed one and two hops upstream of AS18403 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.

Neighbouring networks

1,177

adjacent networks

Upstreams
777%
Peers
84872%
Downstreams
25221%

Networks carrying this one's traffic toward the rest of the internet. Listing the 40 seen on the most AS paths, of 77.

Upstreams of AS18403
NetworkCountryRelationshipPathsVantage pts
AS1299Arelion (fka. Telia Carrier)SEPeer24,72494
AS3356Lumen (Level 3)USPeer23,74184
AS4637Telstra International LimitedHKPeer22,017105
AS6939Hurricane Electric LLCUSPeer21,6577
AS49544i3D.net B.VNLPeer20,0364
AS35280F5 Networks SARLFRPeer19,4456
AS14537Continent 8 LLCUSPeer18,7754
AS18106Viewqwest Pte LtdSGPeer13,8914
AS4229Zenlayer IncUSPeer11,890101
AS23764China Telecom GlobalHKPeer11,1144

Prefixes

All 8,523

The largest blocks AS18403 originates, widest first.

Largest prefixes originated by AS18403
PrefixAddressesVisibility
42.112.0.0/13524k75/76
1.52.0.0/14262k76/76
118.68.0.0/14262k76/76
58.186.0.0/15131k76/76
118.68.0.0/15131k76/76
42.112.0.0/1665.5k76/76
42.113.0.0/1665.5k76/76
42.114.0.0/1665.5k76/76
42.115.0.0/1665.5k76/76
42.116.0.0/1665.5k76/76

Routing health

How AS18403's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.

RPKI origin validation

  • Valid99.7%8,494
  • Invalid0.3%26
  • No ROA<0.1%3

Propagation

  • Globally propagated90% of full-feed peers or more10.5%897
  • Partially propagated40% to 90%53.2%4,537
  • Seen by few peersUnder 40%36.2%3,089

Prefix sizes

IPv4 — 4,771 prefixes

IPv6 — 3,752 prefixes

  • /3017.2B × /64<0.1%1
  • /324.3B × /640.1%4
  • /36268M × /640.5%20
  • /37134M × /640.1%5
  • /418.4M × /64<0.1%1
  • /432.1M × /641.3%50
  • /441M × /6433.4%1,253
  • /45524k × /640.6%21
  • /46262k × /6419.5%731
  • /47131k × /6443.1%1,617
  • /4865.5k × /640.6%23
  • /49 and longerAggregated0.7%26

Recent changes

Announcements that started or stopped since 11th Oct 2026.

621 announced and 602 withdrawn in all; the most recent are shown.

Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.