AT&T IP Lookup

AT&T operates the following Autonomous System Numbers (ASNs): AS7018, AS20057, AS21928. AT&T operates AS7018 (AT&T Internet Services), one of the oldest and largest Tier-1 networks globally, providing both residential DSL/fiber and mobile IP addresses across the continental US. Use our IP lookup tool to identify which specific ASN a AT&T IP belongs to.

AT&T holds multiple IP address blocks allocated by its regional internet registry. These blocks are announced via BGP under AS7018 and AS20057 and AS21928. You can identify AT&T IP addresses using our IP lookup tool — enter any IP and check if the ISP/ASN fields show AT&T.

Enter the IP address in our IP Lookup tool. The ISP and ASN fields will show whether the IP is registered to AT&T (look for AS7018 or AS20057 or AS21928). You can also use our WHOIS Lookup to query the IP's network registration directly from the RIR database.

AT&T provides internet services in: United States, Mexico. IP geolocation for AT&T addresses shows the registered location of the IP block, which may differ from the user's actual city.

AT&T is a mixed (residential + mobile + enterprise) — its customer IPs are generally classified as residential or mobile, not VPN/proxy. However, customers may run VPN servers on AT&T IP addresses, which can cause individual IPs to be flagged.