AS4 University of Southern California - AS4
AS4 is operated by University of Southern California - AS4 and registered with ARIN (US) since 1984-02-22.
It announces 46 IPv4 and 8 IPv6 prefixes, 1% of them RPKI valid.
RIPE RIS sees 12 upstream and peer networks and 3 downstream networks next to it.
PeeringDB lists it with no exchanges or facilities. Its peering policy is open.
| Name | University of Southern California - AS4 |
|---|---|
| Registry handle | ISI-AS |
| Registry (RIR) | ARIN |
| Country | United States (US) |
| Delegated on | 1984-02-22 |
| Network type | Not Disclosed |
| Peering policy | Open |
| Prefixes (IPv4 / IPv6) | 46 / 8 |
| RPKI valid | 1% (1 / 54) |
| Upstreams and peers | 12 |
| Downstream networks | 3 |
| Website | usc.edu |
Routing health
- AS4 announces 46 IPv4 and 8 IPv6 prefixes.
- 1 of 54 announced prefixes are RPKI valid.
- 53 announced prefixes are not covered by a ROA of AS4 (they may have none, or another network’s).
- 12 upstreams and peers, 3 downstream networks seen.
For every check with the fix (IRR route objects, the RPKI state of each route, reverse DNS and the registration), run the full network report.
Announced prefixes 54
- 128.9.0.0/20
- 128.9.16.0/24
- 128.9.17.0/24
- 128.9.18.0/24
- 128.9.19.0/24
- 128.9.26.0/24
- 128.9.28.0/23
- 128.9.30.0/24
- 128.9.31.0/24
- 128.9.32.0/20
- 128.9.34.0/24
- 128.9.35.0/24
- 128.9.36.0/24
- 128.9.37.0/24
- 128.9.38.0/24
- 128.9.40.0/24
- 128.9.43.0/24
- 128.9.44.0/24
- 128.9.46.0/24
- 128.9.47.0/24
- 128.9.48.0/20
- 128.9.64.0/20
- 128.9.80.0/20
- 128.9.96.0/20
- 128.9.112.0/20
- 128.9.113.0/24
- 128.9.117.0/24
- 128.9.122.0/24
- 128.9.123.0/24
- 128.9.127.0/24
- 128.9.128.0/20
- 128.9.144.0/20
- 128.9.160.0/20
- 128.9.176.0/20
- 128.9.192.0/18
- 165.140.12.0/24
- 165.140.13.0/24
- 165.140.14.0/24
- 170.79.218.0/23
- 191.7.35.0/24
- 198.32.16.0/24
- 200.26.255.0/24
- 206.117.6.0/24
- 206.117.27.0/24
- 206.117.31.0/24
- 206.117.37.0/24
- 2001:500:202::/48
- 2001:1878:401::/48
- 2001:1878:402::/48
- 2001:1878:403::/48
- 2001:1878:404::/48
- 2606:d5c0::/32
- 2606:d5c0::/48
- 2804:3edc::/32
Upstreams and peers 12
The networks RIPE RIS sees next to AS4 in BGP paths, the most visible first.
Peering
Peering policy: Open. Suggested max-prefix limits: 0 IPv4, 0 IPv6. PeeringDB record
More about AS4
Sources: RIR delegation data and PeeringDB (updated daily); routing from RIPEstat (RIPE NCC RIS and RPKI), refreshed daily. Routing data from 2026-11-14 13:57 UTC. The country is where the AS number was registered, not necessarily where the network operates.