$ query “AS4” --type=asn → 1 result(s)
AS4 · ISI-AS
University of Southern California
AS4 is run by University of Southern California and is a mid-size transit provider, based in the United States since 1984. The system announces a respectable 67 072 IPv4 addresses, and supports IPv6. The bulk of its IP address space is in the United States, with additional presence in Kenya and Australia, and a smaller footprint in another country. This AS has recently updated its prefix announcements.
- Pioneer — Registered before the year 2000
Basic Information
- Country
- 🇺🇸 United States
- Category
- Education/Research
- Network Role
- Mid-size Transit
- Data Origin
- Authoritative — Metadata from authoritative RIR registry (ARIN, RIPE, APNIC, etc.)
- Registered
- February 22, 1984
- Last Changed
- March 04, 2026
- Last Seen
- April 28, 2026 (active)
Prefix Summary
- IPv4 Prefixes (raw / aggregated)
- 47 / 17
- IPv6 Prefixes (raw / aggregated)
- 7 / 5
- IPv4 Addresses
- 67 072
- Largest IPv4 Prefix
- /17 (32 768 addresses)
- Largest IPv6 Prefix
- /32
- Geolocated Countries
- 🇺🇸 United States (65 536 IPs), 🇰🇪 Kenya (1 024 IPs), 🇦🇺 Australia (768 IPs) and 1 more
- Prefix Changed
- April 27, 2026
Reputation
- Reputation
- Pristine — 0 flagged IPs
Connectivity Summary
- Upstream Providers
- 7 upstreams providing transit
- Peers
- 4 networks exchanging traffic without transit
- Downstream Customers
- 11 downstreams buying transit
- Unclassified
- 1 unclassified BGP neighbor
- Degree
- 23 unique BGP neighbors
- Reach
- 14 networks in customer cone
Upstream Providers (7)
Prefix Lists
IPv4 Prefixes (47 total)
- 128.9.128.0/17 (32 768 addresses (/17 prefix))
- 128.9.64.0/18 (16 384 addresses (/18 prefix))
- 128.9.32.0/19 (8 192 addresses (/19 prefix))
- 128.9.0.0/20 (4 096 addresses (/20 prefix))
- 128.9.16.0/22 (1 024 addresses (/22 prefix))
- 128.9.28.0/22 (1 024 addresses (/22 prefix))
- 165.140.12.0/23 (512 addresses (/23 prefix))
- 170.79.218.0/23 (512 addresses (/23 prefix))
- 196.13.136.0/23 (512 addresses (/23 prefix))
- 128.9.26.0/24 (256 addresses (/24 prefix))
- 43.240.64.0/24 (256 addresses (/24 prefix))
- 165.140.14.0/24 (256 addresses (/24 prefix))
- 198.32.16.0/24 (256 addresses (/24 prefix))
- 206.117.6.0/24 (256 addresses (/24 prefix))
- 206.117.27.0/24 (256 addresses (/24 prefix))
- 206.117.31.0/24 (256 addresses (/24 prefix))
- 206.117.37.0/24 (256 addresses (/24 prefix))
IPv6 Prefixes (7 total)
- 2606:d5c0::/32
- 2001:1878:402::/47
- 2001:500:202::/48
- 2001:1878:401::/48
- 2001:1878:404::/48