FTP logs show numerous failed login attempts

Does anyone know of a way to automatically prevent further access to an FTP service from any IP address that has failed to login correctly more than a certain number of times in a row?

In the past, I've set up security in IIS on this Windows 2003 Server to prevent all access to FTP except for the list I've provided, but that method is not practical in this case.

I've also tried to maintain a list of IP addresses that are NOT allowed access using the logs in \system32\LogFiles\MSFTPSVC1, but many new addresses crop up every day and maintenance is a pain.

I was hoping someone knew of some kind of monitoring device or something that could detect numerous failed attempts within a certain amount of time, then prevent that IP from any further access.Start Free Trial