133.157.20.0/22
Not announced at this prefix length
No announcement covering 133.157.20.0/22 was visible from any of our collectors at the last snapshot. That can mean the space is unrouted, or that it is announced only within a network we have no vantage point inside.
At a glance
Addresses
/22 block
Visibility
RPKI
Registry
JPAllocated 1st March 1997
AS paths to this prefix
No AS paths are stored for this prefix. We keep the full path from one reference peer per collector rather than from every peer, so a prefix only has paths here once it has been seen by one of those peers.
Registry and RPKI
- RIR
- APNIC — Asia-Pacific
- Country
- Japan
- Allocated
- 1st March 1997
- Allocation block
- 133.0.0.0/8
- Status
- allocated
- Origin validation
- Unknown
Prefix hierarchy
Announcements above, below and beside this one in the real routing table.
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
No less specific announcement covers this prefix.
More specific announcements
| Prefix | Addresses | Origin | Visibility |
|---|---|---|---|
| 133.157.20.0/24 | 256 | AS6282Fiber Optical Network LLC | 76/76 |
| 133.157.21.0/24 | 256 | AS6282Fiber Optical Network LLC | 76/76 |
| 133.157.22.0/24 | 256 | AS6282Fiber Optical Network LLC | 76/76 |
| 133.157.23.0/24 | 256 | AS6282Fiber Optical Network LLC | 76/76 |
Sibling prefixes
No prefix of the same length in the same parent block is announced.
History
- AS5832512th October 2026 — 31st October 2026
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 133.157.20.0/22 in the calculator/22 reference
Routing data derived from RouteViews MRT archives and public registry data.