Search every site and mailbox for IP addresses.
Data explorer counts sensitive data. eDiscovery shows where it is, and lets you combine it with age. In a separate case with eDiscovery (Premium), we search all SharePoint and OneDrive sites for IP addresses, read the statistics and the top 100, do the same for mailboxes, and narrow it down to what is both sensitive and older than 2020. And regex? That belongs in a custom sensitive information type.