128.104.0.0/16
🇺🇸CIDR
128.104.0.0/16
IP Version
IPv4
Addresses
65.5K
Mask
/16 (255.255.0.0)
Country
🇺🇸 United States
City
Madison
RIR
ARIN
Status
allocated
Allocated
1/29/1986
Announced BGP Routes
1 of 1 routeRPKI:
IRR:
| Prefix | Origin AS | RPKI | IRR | Last Seen |
|---|---|---|---|---|
| 128.104.0.0/16 | AS59WISC-MADISON-AS - University of Wisconsin Madison | Valid | ARIN | 5/31/2026 |
Covering Prefix
1 less-specific announcement| Prefix | Origin AS | RPKI | IRR | Last Seen |
|---|---|---|---|---|
| 128.104.227.0/24 | AS59WISC-MADISON-AS - University of Wisconsin Madison | Valid | — | 5/31/2026 |
Geolocation
API
Open https://api.ipctl.io/v1/prefix/128.104.0.0/16Returns prefix allocation, BGP routes, and more-specific subnets.
curl -s "https://api.ipctl.io/v1/prefix/128.104.0.0/16" | jq
External Links