The Internal Revenue Service's Active Directory has too many forests, says the Treasury Inspector General for Tax Administration.

In addition, network scans show that 727 Windows servers and 238 workstations reside in unauthorized domains, auditors say in a report dated Sept. 23 that wasn't posted online until Oct. 16.

According to the audit, the tax agency operates approximately 6,000 servers and 110,000 workstations using Microsoft (NASDAQ: MSFT) Windows operating systems. It set up Active Directory during fiscal 2005; eight IRS organizations maintain 20 forests, the report says.

Fourteen of those forests should be eliminated, TIGTA says, noting that one consists of Windows 2000 servers, which Microsoft stopped supporting in July 2010.

The IRS pays IBM $1.2 million annually to maintain the forest, auditors say--but IRS officials told auditors that the money does not represent an inefficient use of resources. The equipment in the forest "is required to support critical financial management and accounting functions," says the official IRS response to the audit, signed by IRS Chief Technology Officer Terry Milholland.

Nonetheless, that particular forest will be shut down, IRS information technology officials told auditors. IT officials will study the costs and technical issues of shutting down the other ones, they also said.

When it comes to networked machines residing outside of a valid Active Directory domain, IT officials told auditors that there may exist valid for reasons for the set up, but that it would take massive man hours to make a correct determination. Auditors don't recommend that the rogue--or are they?--machines be immediately shut down, just that the IRS have process in place to prevent servers or workstations from being connected to the network without authorization and documentation.

The tax agency should continue to scan its network for unauthorized machines, auditors also say.

For more:
- download the audit, 2011-20-111 (.pdf)

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