subnet.im

AS42353Simwood eSMS Limited

United KingdomRegistryRIPE NCC

As of 13th November 2026, AS42353 (Simwood eSMS Limited), a network registered in the United Kingdom with RIPE NCC, originates 16 IPv4 prefixes covering 6.4k addresses. By IPv4 address space that makes it the 13,929th-largest of the 80,825 networks we see originating IPv4, and the 415th-largest of 2,124 in the United Kingdom. It is seen behind 7 upstream networks, most often AS2914 (NTT America, Inc.) and AS174 (Cogent Communications, LLC). 94% of its announcements have a valid RPKI ROA, and none are RPKI-invalid. 100% of its routes reach at least 90% of full-feed peers.

At a glance

IPv4 prefixes

16

IPv6 prefixes

0

IPv4 addresses

6.4k

IPv6 /64s

0

Upstream graph

The networks AS42353 is seen behind, one and two hops out, drawn from real AS paths.

AS42353Toward the internet core
Upstream graph for AS42353: 12 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS42353Simwood eSMS Limi…This networkAS174Cogent Communicat…AS2914NTT America, Inc.AS3170VeloxServ Communi…AS6939Hurricane Electri…AS13237euNetworks GmbHAS151326DCConnect Communi…AS49544i3D.net B.VAS215859Hetzner Cloud - S…AS1299Arelion (fka. Tel…AS3257GTT Communication…AS20130Depaul UniversityAS132337Axclusive

Networks observed one and two hops upstream of AS42353 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

20

adjacent networks

Upstreams
735%
Peers
1365%
Downstreams
00%

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

Upstreams of AS42353
NetworkCountryRelationshipPathsVantage pts
AS2914NTT America, Inc.USPeer92578
AS174Cogent Communications, LLCUSPeer29532
AS6939Hurricane Electric LLCUSPeer123
AS41811CONVERGENCE (GROUP NETWORKS) LIMITEDGBPeer41
AS13237euNetworks GmbHDEPeer41
AS3170VeloxServ Communications LtdGBPeer41
AS24482SG.GSSGPeer41

Prefixes

The largest blocks AS42353 originates, widest first.

Largest prefixes originated by AS42353
PrefixAddressesVisibility
178.22.136.0/212k78/78
178.22.136.0/2351278/78
178.22.140.0/2351278/78
91.233.5.0/2425678/78
178.22.136.0/2425678/78
178.22.137.0/2425678/78
178.22.139.0/2425678/78
178.22.140.0/2425678/78
178.22.141.0/2425678/78
178.22.142.0/2425678/78

Routing health

How AS42353'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

  • Valid93.8%15
  • Invalid0.0%0
  • No ROA6.3%1

Propagation

  • Globally propagated90% of full-feed peers or more100.0%16
  • Partially propagated40% to 90%0.0%0
  • Seen by few peersUnder 40%0.0%0

Prefix sizes

IPv4 — 16 prefixes

Recent changes

Announcements that started or stopped since 14th Oct 2026.

No announcement by AS42353 started or stopped in this period.

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