The IInetLogInformation::GetClientHostName method obtains the IP address of the client.
virtual LPSTR STDMETHODCALLTYPE GetClientHostName(
IN PCHAR pszClientHostName,
IN PDWORD pcbSize
);
Logging modules should query for this method if a server instance has set the LogExtFileClientIp flag of the LogExtFileFlags metabase identifier.
LogExtFileClientIp, LogExtFileFlags