NT Authority\Anonymous Logon Failure

Hello,

In AX 2009 SP1, what are the services that requires NT AUTHORITY \ ANONYMOUS Logon.

The reason I ask is we have been using DOMAIN NAME \ MSAXSERVICE service account logon and Application is working just fine. No users have any complain on failing or not gettign the application services that we have on Prod. But, the SQL server keeps getting Log in attempts for User NT AUTHORITY \ ANONYMOUS logon and keep failing 3 times in a minute. The error log in filling up.

Any help is greatly appreciated.

Thanks