IP Anonymization in Analytics
At a glance
When a customer of Analytics requests IP address anonymization, Analytics anonymizes the address as soon as technically feasible at the earliest possible stage of the collection network. The IP anonymization feature in Analytics sets the last octet of IPv4 user IP addresses and the last 80 bits of IPv6 addresses to zeros in memory shortly after being sent to the Analytics Collection Network. The full IP address is never written to disk in this case.
The Analytics Collection Network
When a request for ga.js, analytics.js, _utm.gif, or /collect arrives, it includes additional information in the HTTP request header (i.e. the type of browser being used) and the TCP/IP header (i.e. the IP address of the requester).