IP Addresses

AT&T Services, Inc. provides IP addresses and IP ranges as public usage for the following purposes:

• To identify the originating carrier as AT&T
• To identify Layer 3 of the mobile web traffic origination source
• To filter HTTP headers from a trusted source including x-up-subno, x-up-calling-line-id, x-acr and x-up-sgsn-ip (when applicable)
• To identify AT&T initiated mobile web traffic for use in source based routing and balanced DNS traffic management

Download the list of IPv6 addresses.