216.21.18.0/24
At a glance
Addresses
/24 block
Visibility
76 of 80 vantage points
RPKI
Registry
USAllocated 8th July 2015
AS paths to this prefix
All pathsOne observed path, hop by hop, from the origin out to Oregon, US.
Seen from Oregon, US
- Peer of AS5721seen on 76 paths from 76 vantage points
- Peer of AS33657seen on 24,699 paths from 142 vantage points
- Peer of AS7922seen on 2,385 paths from 1 vantage point
- Peer of AS23352seen on 103,654 paths from 1 vantage point
One path, hop by hop, from the origin outward to the vantage point that saw it. Counts beside each step are how often we see that pair adjacent anywhere in the table, not how often this path was used — BGP carries no traffic figures.
Every path we see
- London, UK57213365733568529This path
- Sao Paulo5721336573356266213This path
- Singapore57213365779221299132337This path
- Oregon, US57213365779222335220130Shown above
- Amsterdam572133657792217434549213151This 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
95%
Seen by 76 of 80 full-feed vantage points
Globally propagatedObserved 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
- ARIN — North America
- Country
- United States
- Allocated
- 8th July 2015
- Allocation block
- 216.21.18.0/23
- Status
- allocated
- 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.
Covering announcements
No less specific announcement covers this prefix.
More specific announcements
Nothing inside this block is announced separately.
Sibling prefixes
| Prefix | Addresses | Origin | Visibility |
|---|---|---|---|
| 216.21.19.0/24 | 256 | AS5721National Defense University | 80/80 |
History
- AS572112th 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 216.21.18.0/24 in the calculator/24 reference
Routing data derived from RouteViews MRT archives and public registry data.