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AS39588Mimecast Services Limited

United KingdomRegistryRIPE NCC

As of 11th November 2026, AS39588 (Mimecast Services Limited), a network registered in the United Kingdom with RIPE NCC, originates 12 IPv4 prefixes covering 3.6k addresses and 2 IPv6 prefixes. By IPv4 address space that makes it the 19,328th-largest of the 80,747 networks we see originating IPv4, and the 590th-largest of 2,122 in the United Kingdom. It is seen behind 3 upstream networks, most often AS6461 (Zayo Bandwidth) and AS3356 (Lumen (Level 3)). 79% of its announcements have a valid RPKI ROA, and none are RPKI-invalid. 71% of its routes reach at least 90% of full-feed peers, and 4 prefixes are also originated by another network.

At a glance

IPv4 prefixes

12

IPv6 prefixes

2

IPv4 addresses

3.6k

IPv6 /64s

131k

Upstream graph

The networks AS39588 is seen behind, one and two hops out, drawn from real AS paths.

AS39588Toward the internet core
Upstream graph for AS39588: 8 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS39588Mimecast Services…This networkAS3356Lumen (Level 3)AS6461Zayo BandwidthAS24989Equinix (Germany)…AS3549Lumen (fka. Globa…AS2914NTT America, Inc.AS32590Valve CorporationAS15830Equinix, Inc.AS35280F5 Networks SARL

Networks observed one and two hops upstream of AS39588 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

7

adjacent networks

Upstreams
343%
Peers
457%
Downstreams
00%

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

Upstreams of AS39588
NetworkCountryRelationshipPathsVantage pts
AS6461Zayo BandwidthUSPeer37594
AS3356Lumen (Level 3)USPeer22168
AS24989Equinix (Germany) GmbHDEPeer20892

Prefixes

The largest blocks AS39588 originates, widest first.

Largest prefixes originated by AS39588
PrefixAddressesVisibility
194.104.108.0/2351276/76
194.104.110.0/2351276/76
41.74.203.0/2425615/76
51.163.158.0/2425676/76
51.163.159.0/2425676/76
62.140.7.0/2425676/76
62.140.10.0/2425676/76
147.28.34.0/2425676/76
147.28.35.0/2425676/76
170.10.142.0/2425614/76

Routing health

How AS39588'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

  • Valid78.6%11
  • Invalid0.0%0
  • No ROA21.4%3

Propagation

  • Globally propagated90% of full-feed peers or more71.4%10
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%28.6%4

Prefix sizes

IPv4 — 12 prefixes

IPv6 — 2 prefixes

  • /4865.5k × /64100.0%2

Recent changes

Announcements that started or stopped since 12th Oct 2026.

No announcement by AS39588 started or stopped in this period.

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