The audit trail log records a history of activity logged by DNS and DHCP servers. You can use the Audit Trail log to diagnose network trends. A DNS audit trail would include a history of DNS queries and the hosts requesting them. A DHCP audit trail would include a history of address assignments, including which host had an address during a given period of time and a list of addresses that had already been in use when pinged.
If you have set the Enable Audit Trail Log parameter on a server's Option tab page, you can use the View Audit Trail Log button on the tool bar to view the audit trail log.
Refer to Configuring DNS Auditing for information about configuring a DNS server for auditing. Refer to Configuring DHCP Auditing for information about configuring a DHCP server for auditing.