subnet.im

AS15404COLT Technology Services Group Limited

United KingdomRegistryRIPE NCC

As of 28th September 2026, AS15404 (COLT Technology Services Group Limited), a network registered in the United Kingdom with RIPE NCC, originates 147 IPv4 prefixes covering 146k addresses and 9 IPv6 prefixes. By IPv4 address space that makes it the 1,688th-largest of the 79,556 networks we see originating IPv4, and the 37th-largest of 2,074 in the United Kingdom. It is seen behind 1 upstream network, most often AS8220 (COLT). 67% of its announcements have a valid RPKI ROA, and none are RPKI-invalid. 98% of its routes reach at least 90% of full-feed peers, and 3 prefixes are also originated by another network.

At a glance

IPv4 prefixes

147

IPv6 prefixes

9

IPv4 addresses

146k

IPv6 /64s

4.6B

Upstream graph

The networks AS15404 is seen behind, one and two hops out, drawn from real AS paths.

AS15404Toward the internet core
Upstream graph for AS15404: 3 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS15404COLT Technology S…This networkAS8220COLTAS3356Lumen (Level 3)AS15576NTS workspace AG

Networks observed one and two hops upstream of AS15404 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

2

adjacent networks

Upstreams
150%
Peers
150%
Downstreams
00%

Networks carrying this one's traffic toward the rest of the internet.

Upstreams of AS15404
NetworkCountryRelationshipPathsVantage pts
AS8220COLTGBPeer12,482146

Prefixes

All 156

The largest blocks AS15404 originates, widest first.

Largest prefixes originated by AS15404
PrefixAddressesVisibility
161.17.0.0/1665.5k82/82
62.85.160.0/198.2k82/82
194.59.96.0/198.2k82/82
5.11.96.0/204.1k82/82
148.188.0.0/204.1k82/82
148.188.192.0/204.1k82/82
193.29.144.0/204.1k82/82
148.188.232.0/212k82/82
178.249.200.0/212k82/82
194.99.120.0/212k82/82

Routing health

How AS15404'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

  • Valid66.7%104
  • Invalid0.0%0
  • No ROA33.3%52

Propagation

  • Globally propagated90% of full-feed peers or more98.1%153
  • Partially propagated40% to 90%0.6%1
  • Seen by few peersUnder 40%1.3%2

Prefix sizes

IPv4 — 147 prefixes

IPv6 — 9 prefixes

  • /324.3B × /6411.1%1
  • /36268M × /6411.1%1
  • /4865.5k × /6477.8%7

Recent changes

Announcements that started or stopped since 29th Aug 2026.

  • Withdrawn2a10:4780:8261::/4824th Sept 2026
  • Announced2a10:4780:8261::/4822nd Sept 2026
  • Withdrawn103.80.220.0/2421st Sept 2026
  • Withdrawn103.80.221.0/2421st Sept 2026

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