Dynamic Host Configuration Protocol version 6 (DHCPv6) runtime includes normal operating functions of the DHCPv6 server. Examples of these functions include lease issuance and rogue detection.

Dynamic Host Configuration Protocol version 6 (DHCPv6) servers include several logging features and server parameters that provide enhanced auditing capabilities. You might need to configure log settings to prevent the log from filling up or to give the server permissions to write to the log. You can configure the following properties to keep your DHCP server logs healthy:

• The audit log file path

• A maximum size restriction

• An interval for disk checking

• A minimum size requirement

DHCPv6 has determined that the audit log cannot be written to because it is full or cannot be accessed. The DHCP server will continue to function properly, but audit events will not be recorded until the log is writable.

Resolution: Remove old audit log files or increase the maximum audit log size

If the disk is full or the maximum log size is reached, the DHCP server closes the current file and ignores further requests to log audit events until either midnight or until disk status is improved and the disk is no longer full. If the disk is full, you can add more physical disk space, increase the maximum audit log size, or delete old log files from the default log directory: %windir%\System32\Dhcp.

To perform these procedures, you must be a member of the Administrators group, or you must have been delegated the appropriate authority.

To increase the maximum audit log size:

Caution: Incorrectly editing the registry might severely damage your system. Before making changes to the registry, you should back up any valued data.

• Click Start, type regedit in Start Search, click Continue, and then press ENTER.

• In the registry tree, navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DHCPServer\Parameters, and then press ENTER.

• Double click DhcpLogFilesMaxSize, select Decimal, and then type a number greater than the current number in Value data.