128.231.0.0/16
🇺🇸CIDR
128.231.0.0/16
IP Version
IPv4
Addresses
65.5K
Mask
/16 (255.255.0.0)
Country
🇺🇸 United States
City
Bethesda
RIR
ARIN
Status
allocated
Allocated
5/6/1987
Announced BGP Routes
1 of 1 routeRPKI:
IRR:
| Prefix | Origin AS | RPKI | IRR | Last Seen |
|---|---|---|---|---|
| 128.231.0.0/16 | AS3527NIH-NET - National Institutes of Health | Valid | ARINRADB | 5/30/2026 |
Covering Prefix
2 less-specific announcements| Prefix | Origin AS | RPKI | IRR | Last Seen |
|---|---|---|---|---|
| 128.231.3.0/24 | AS3527NIH-NET - National Institutes of Health | Valid | — | 5/30/2026 |
| 128.231.245.0/24 | AS3527NIH-NET - National Institutes of Health | Valid | — | 5/30/2026 |
Geolocation
API
Open https://api.ipctl.io/v1/prefix/128.231.0.0/16Returns prefix allocation, BGP routes, and more-specific subnets.
curl -s "https://api.ipctl.io/v1/prefix/128.231.0.0/16" | jq
External Links