SUBNET.IM

155.136.200.0/23

Natwest Markets PLCAS21301

Natwest Markets PLCAS21054

Announced by more than one origin AS (MOAS).

At a glance

Addresses

512

/23 block

Visibility

61%

49 of 80 vantage points

RPKI

No ROA

Registry

RIPE NCCGB

Allocated 8th November 1991

AS paths to this prefix

One real path per vantage point, fanning out from the origin. Where two reach the prefix the same way, those hops are drawn once. Open a path to follow it hop by hop.

OriginVantage points
AS path graph: 5 observed paths to 155.136.200.0/23, fanning out from AS21054, AS21301 toward the vantage points that see it. Each path is written out in full beneath the graph.AS21301Natwest Markets P…OriginAS1273Vodafone Group PLCAS1299Arelion (fka. Tel…AS8529Zain Omantel Inte…AS3356Lumen (Level 3)AS266213PLANETCLICK TELEC…AS21054Natwest Markets P…OriginAS1273Vodafone Group PLCAS1299Arelion (fka. Tel…AS132337AxclusiveAS6939Hurricane Electri…AS20130Depaul UniversityAS2914NTT America, Inc.AS34549meerfarbig GmbH &…AS213151Christian Elsen
  1. London, UK21301127312998529This path
  2. Sao Paulo2130112733356266213This path
  3. Singapore2105412731299132337This path
  4. Oregon, US213011273693920130This path
  5. Amsterdam210541273291434549213151This path

Each row is one path genuinely present in the routing table at our last snapshot, read outward from the origin to the vantage point that saw it. Open a row to follow that one path hop by hop. A heavier line in the graph means more vantage points reach the prefix that same way.

Route visibility

61%

Seen by 49 of 80 full-feed vantage points

Partially propagated

Observed at 5 of our collectors.

What this percentage counts

The denominator counts only full-feed peers — peers carrying a substantially complete routing table at the moment of the snapshot. IXP route-server peers usually feed partial tables and are excluded, because including them would make a normally propagated prefix look as though half the internet could not see it.

It measures how widely an announcement has spread across the networks we can observe. It says nothing about whether the prefix is reachable from any particular place, or how it performs.

Registry and RPKI

RIR
RIPE NCC — Europe, Middle East, Central Asia
Country
United Kingdom
Allocated
8th November 1991
Allocation block
155.136.0.0/16
Status
assigned
Origin validation
No ROA

No ROA covers this prefix, so RPKI has nothing to say about it either way. This is still the common case for a large share of the routing table.

Prefix hierarchy

Announcements above, below and beside this one in the real routing table.

CoveringMore specific
Prefix hierarchy for 155.136.200.0/23: the announcements covering it on the left, the announcements inside it on the right. Every prefix drawn is also listed in the tables below.155.136.128.0/17AS21054155.136.0.0/16AS21054155.136.202.0/23AS21054155.136.200.0/23AS21301This prefix155.136.202.0/23AS21301155.136.200.0/24AS21301155.136.201.0/24AS21301

Left to right is specificity: a shorter mask covering more address space, then this prefix, then the announcements carved out inside it. Only the first few of each are drawn — the tables below list them all.

Covering announcements

Announcements that contain 155.136.200.0/23
PrefixAddressesOriginVisibility
155.136.128.0/1732.8kAS21054Natwest Markets PLC80/80
155.136.0.0/1665.5kAS21054Natwest Markets PLC80/80

More specific announcements

Announcements contained within 155.136.200.0/23
PrefixAddressesOriginVisibility
155.136.200.0/24256AS21301Natwest Markets PLC80/80
155.136.201.0/24256AS21301Natwest Markets PLC80/80

Sibling prefixes

Prefixes of the same length sharing a parent block with 155.136.200.0/23
PrefixAddressesOriginVisibility
155.136.202.0/23512AS21054Natwest Markets PLC30/80
155.136.202.0/23512AS21301Natwest Markets PLC50/80

History

  1. AS2130112th August 2026 — present
  2. AS2105412th August 2026 — present
Why these dates start where they do

A first-seen date is the first time we saw that origin, not the first time it appeared in BGP. Our history is forward-only with no backfill, so it says nothing about the period before we started collecting — treat the earliest dates with suspicion.

Open 155.136.200.0/23 in the calculator/23 reference

Routing data derived from RouteViews MRT archives and public registry data.