Performance Monitor, DNS, and LDAP Bugs

Performance Monitor Bug Fix
Performance Monitor might display data incorrectly when you use saved chart settings from the .pmc files to view Performance Monitor log file data. If you open the log file in Performance Monitor and the saved chart settings load from a .pmc file with the counters from multiple computers, Performance Monitor might display some counters with no data, instead of the data that has collected in the log file.

Performance Monitor displays the correct data for the counters for the first computer logged in the Performance Monitor log file. (Performance Monitor also shows the correct data values and works as expected when you add the counters manually.) However, when it uses saved chart settings from multiple computers, Performance Monitor might not retrieve data correctly beyond the first computer's counters. Here's what happens.

Performance Monitor reads a system name from a counter saved in the .pmc file and tries to retrieve the log file data for that system counter. However, Performance Monitor searches for that counter's data only in the first computer's logged data. Therefore, it doesn't retrieve correct data for counters other than those of the first system whose data is logged in the log file.

Microsoft Support Online article Q254384 documents the problem. Call Microsoft Support for a new version of Performance Monitor that corrects the log file issues for all versions of Windows NT through Service Pack 6a (SP6a). The new perfmon.exe release has a file date of April 25, 2000.

DNS Bug Fix
When you try to clear Windows 2000's DNS cache, you might receive the error message, "The server cache cannot be cleared. DNS zone already exists in the directory service." If you try to clear the cache from the command line (e.g., using dnscmd /clearcache), you might see the error message, "failed: status = 9718 (0x000025f6)." Microsoft Support Online article Q257828 indicates that you can call Microsoft Support for a new version of dns.exe that correctly purges the cache.

LDAP Sessions Don't Time Out
In Win2K, the timeout mechanism for Lightweight Directory Access Protocol (LDAP) might not work, and old connections might remain connected. The scheduler thread that determines when to time out LDAP connections doesn't correctly handle the rollover of the 32-bit time value that the GetTickCount function returns. When a rollover occurs, the server stops timing out inactive connections. As a result, you can have hundreds of stale LDAP connections on a computer. Although this problem doesn't prevent LDAP connections to the server, the stale connections continue to use system resources until you reboot the server. Microsoft Support Online article Q258066 documents this problem; no fix or workaround is currently available.

Internet Connection Sharing Problem
Every Win2K system supports Internet Connection Sharing (ICS) via Point-to-Point Protocol (PPP). When you implement this feature, clients that share the connection might experience problems browsing a Web site or sending email with attachments. Microsoft Support Online article Q259783 indicates that Win2K's PPP implementation over Ethernet requires that you lower the network Maximum Transmission Unit (MTU) setting to a value of 1492 on all systems that share an Internet connection. The default MTU setting is typically 1500. To adjust the MTU setting, you must edit the Registry parameters for the network adapter on all affected clients. Microsoft Support Online article Q120642 documents the parameters.

In Win2K, the MTU for a specific network adapter resides in the Registry entry Tcpip\Parameters\Interfaces\<Adapter ID> and has a data type of REG_DWORD. Read both Microsoft Support Online articles carefully before making any modifications to the default network packet size because altering the MTU modifies the packet size for all network traffic. I also highly recommend that you test all affected systems thoroughly before you release this fix to production.

Multiple Monitors Use All Available System Page Table Entries
When you run Win2K with multiple monitors, the system might run out of system page table entries (PTEs) required to map the monitors' frame buffers. Microsoft Support Online article Q226064 documents a Registry modification you can make to increase the default number of PTEs and avoid this problem. Registry path HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management specifies the number of PTEs. Increase the value entry SystemPages:REG_DWORD to 36000. The article doesn't recommend a reboot, but I’m fairly certain that you need to restart your system to activate this change.

Third-Party Audio CD Players
If you insert an audio CD after you install and then uninstall a third-party audio CD player using Add/Remove Programs, Win2K might not play the CD automatically and might instead respond with the error message, "Access to the specified device, path, or file is denied." Some third-party drivers modify the path that defines the program that plays CDs. When you remove the driver, the removal procedure doesn't correctly restore the CD path setting.

To restore the CD autorun feature, you must manually edit a system .inf file and remove and reinstall the Win2K multimedia component. To see the system .inf file, you must disable the Hide System Files option in Windows Explorer. Go to %SystemRoot%\Inf\, open sysoc.inf in Notepad, and, in the Old Base Components section, change the line


Next, locate the line AccessUtil=" and remove the "Hide" comment. If you leave this option hidden, none of the other components in the Old Base Components section will appear in the Add/Remove Programs tool. Save and close sysoc.inf. Then remove and reinstall the Win2K multimedia components and reboot. Microsoft Support Online article Q259473 documents the steps you follow to restore CD player functionality.

TAGS: Security
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