1001 Secrets for Windows NT Registry
(Publisher: 29th Street Press)
Author(s): Tim Daniels
ISBN: 1882419685
Publication Date: 12/01/97

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NetLogon

The NetLogon service manages the process of logging on to a domain. It interacts with the NT Local Security Authority (LSA) to validate account and password information. It also keeps all account information synchronized between the Primary Domain Controller (PDC) and the Backup Domain Controllers (BDCs).

VI-30 NetLogon collects account information for a specified period of time and sends it in one batch to each BDC that isn’t already up-to-date. By default, NetLogon determines the interval based on the server’s load, but you can tune the time period NetLogon collects account data to suit your environment or to minimize network traffic.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\Netlogon\Parameters
Value Name: Pulse
Data Type: REG_DWORD
Value: 300

The value is the number of seconds in the collection period. The default value is 300 seconds, or 5 minutes. Valid values range from 60 to 172,800 (48 hours).

VI-31 When a BDC receives a pulse from the PDC, it waits a specified time before returning a message. Changing this entry changes the wait period.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\Netlogon\Parameters
Value Name: Randomize
Data Type: REG_DWORD
Value: 1

The value is the number of seconds that a BDC waits before requesting updated information from a PDC after receiving a pulse. The default value is 1; valid values range from 0 to 120. Typically, you should keep this value small, less than the PulseTimeout1 value under the same key.

VI-32 The following entry specifies how many outstanding pulses the PDC has at any time. By adjusting this value you can control the load on a PDC — the higher the value, the higher the potential load when security or account information is updated. Decreasing the value increases the time required to propagate the information to all the BDCs. You can estimate the time it takes to replicate account or security database information with the formula ((Randomize/2) * NumberOfBdcsInDomain) / PulseConcurrency

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\Netlogon\Parameters
Value Name: PulseConcurrency
Data Type: REG_DWORD
Value: 20

The value is the number of outstanding pulse events the PDC allows. The default value is 20; valid values range from 0 to 500.

TCP/IP

VI-33 TCP/IP allows a certain number of bytes to be sent before the system waits for an acknowledgment. You can increase this number, also known as the Window Size, if your network is reliable and has high bandwidth. Ideally, it should be a multiple of the TCP Maximum Segment Size (MSS).

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\Tcpip\Parameters
Value Name: TcpWindowSize
Data Type: REG_DWORD
Value: 8760

The value is the size, in bytes, of the TCP/IP window. The default is 8760 in Ethernet networks; valid values range from 0 to 0xFFFF.

NWLink

NWLink is an implementation of the IPX/SPX protocols popular in NetWare networks. The NWNBLink module provides support for the Novell implementation of the NetBIOS protocol.

VI-34 By default, the NWNBLink protocol allocates two frames to receive messages. When the frames are filled, it sends an acknowledgment to the sender. This entry is typically used as a clocking mechanism where the sender is on a fast part of the LAN but the receiver is on a slow link. You can set the value to 0 to prevent NWNBLink from sending any acknowledgments, which can improve performance. Note that you can direct NWNBLink to ignore the AckWindow if round-trip times are below a threshold indicated in the AckWindowThreshold value under the same key.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\Parameters
Value Name: AckWindow
Data Type: REG_DWORD
Value: 2

VI-35 Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\Parameters
Value Name: AckWindowThreshold
Data Type: REG_DWORD
Value: 2

The value determines the number of frames in the AckWindow that are filled with received messages before NWNBLink sends an acknowledgment. If the value is 0, not acknowledgments are sent. The default value is 2.

VI-36 While NWNBLink sessions are initialized, the maximum number of messages that the receiver can process at one time is transmitted to the sender. Increasing this value may increase performance on high-bandwidth networks.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Services\NWNBLink\Parameters
Value Name: RcvWindowMax
Data Type: REG_DWORD
Value: 4

The value sets the number of frames allocated for receiving message. The default value is 4. Valid values range from 0 to 49152.


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