REG: Network Services Entries, Part 3

• Windows NT operating system version 3.1
• Windows NT Advanced Server version 3.1

SUMMARY

The article contains Registry entries for network services, Part 3. These subgroups are included:

• BootVerification Service
• Browser Service
• DiskPerf Service
• DLC System Driver

BootVerification Service Entries

The Services subkey for the BootVerification service does not appear by default in the Registry. You can add this key if you want to verify system startup from a remote location using the BOOTVRFY.EXE program provided with Windows NT. This service can be started from a remote computer. The service tells the Windows NT service controller that it should save the current startup system configuration as the LastKnownGood control set, and then the service terminates itself.

When you add the BootVerification key using the Registry Editor, add the following value entries:

   Value entry     Data type          Value               Comment
   --------------------------------------------------------------
   ErrorControl    REG_DWORD          0x1                 Normal
   ImagePath       REG_EXPAND_SZ      bootvrfy.exe          -
   ObjectName      REG_SZ             LocalSystem           -
   Start           REG_DWORD          0x3                 Demand
   Type            REG_DWORD          0x2                 Win32 shared
                                                          process

   HKEY_LOCAL_MACHINE\Software\Windows NT\CurrentVersion\WinLogon

This alternative method of verifying system startup cannot be used in conjunction with BootVerificationProgram (as described earlier in this chapter).

Browser Service Entries

The parameters that control network bindings for the Browser service are described in "NetRules Subkey Entries" in the article "Network Adapter Cards Entries, Part 1."

Under the following Registry path, two parameters are found:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Browser\Parameters

CacheHitLimit     REG_DWORD     0 to 256
   Describes the number of NetServerEnum requests required to qualify
   that the response to a NetServerEnum request be cached. If the
   browser receives more than CacheHitLimit NetServerEnum requests
   with a particular set of parameters, it caches the response and
   returns that value to the client. Default: 1

CacheResponseSize     REG_DWORD     0 to xffffffff
   Specifies the maximum number of responses kept for each transport.
   To disable this feature, set this value to 0. Default: 10

IsDomainMasterBrowser     REG_SZ     Boolean
   For TCP/IP, specifies a workstation within a workgroup which can be
   included in global LMHOSTS file. When this parameter is set to Yes,
   it forces the elevation of a workstation's priority for the
   browser. This helps with WAN browsing.

   This value should be set on a few systems for the workgroup,
   placing mappings for each in the global LMHOSTS file. For example,
   in a workgroup with 20 members, set this value on three of the
   computers to earn a better chance to act as master browsers. This
   facilitates remote browsing ability for workstations in remote
   domains whose domain master browser has successful mappings for
   these special workgroup members.

MaintainServerList     REG_SZ     Boolean or Auto
   If this value is No, this server is not a browse server. If this
   value is Yes, this server becomes a browse server. It attempts to
   contact the Master Browse Server to get a current browse list. If
   it cannot find the Master Browse Server, it forces an election and
   is, of course, a candidate to become the master.

   If MaintainServerList is Auto, this server may or may not become a
   browse server, depending on the results of the Registry exchange
   with the Master Browse Server.

   If MaintainServerList is set to Yes, the computer is configured to
   always be a backup browser.

   Default: Auto, if none is present. (This server contacts the Master
   Browse Server, and the Master Browse Server tells this server
   whether it should become a browse server.)

QueryDriverFrequency     REG_DWORD     0 to 900
   Indicates the time after which a browser master will invalidate its
   NetServerEnum response cache and the frequency that a master
   browser will query the browser driver to retrieve the list of
   servers. Increasing this time makes browsing somewhat faster, but
   browse information will not necessarily be 100 percent accurate to
   the minute. Lowering this time makes browse response more accurate,
   but will increase the CPU load on the browse master. Default: 30

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DGRcvr\Parameters

BrowserServerDeletionThreshold     REG_DWORD
BrowserDomainDeletionThreshold        REG_DWORD     0 to 0xffffffff
   If more than BrowserServerDeletionThreshold servers (or
   BrowserDomainDeletionThreshold) servers (or domains) are flushed in
   a 30-second interval, this will cause an event to be generated.
   Default: 0xffffffff

FindMasterTimeout     REG_DWORD     0 to 0xfffffff
   Specifies the maximum number of seconds that FindMaster requests
   should be allowed to take. If you have a slow LAN, you may want to
   increase this value (but only if directed by Microsoft Product
   Support services). Default: 0xffffffff

GetBrowserListThreshold     REG_DWORD     Number
   Represents the threshold that the Browser uses before logging an
   error indicating that too many of these requests have been
   "missed." If more requests than the value of GetBrowserServerList
   are missed in an hour, the Browser logs an event indicating that
   this has happened. Default: 0xffffffff (That is, never log events.)

MailslotDatagramThreshold      REG_DWORD     Number
   Represents the threshold that the Browser uses before logging an
   error indicating that too many of these requests have been
   "missed." If more mailslots than the value of
   MailslotDatagramThreshold are missed in an hour, the Browser logs
   an event indicating that this has happened. Default: 0xffffffff
   (That is, never log events.)

DiskPerf Service Entries

The DiskPerf subkey entries determines whether disk performance statistics are maintained by the system. If the Start value is 0 (boot), then statistics are counted and are reported by Performance Monitor and similar tools. Collecting disk performance statistics can take up to 1.5 percent of the disk throughput on a system with a slow processor (such as an 20 MHz 80386 computer) but should have negligible impact on a system with a faster processor (such as a 33 MHz i486 and above).

Turn DiskPerf on or off only by using the Diskperf utility; for example, type diskperf -y at the command prompt.

The Registry path is:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DiskPerf

  Value Entry     Value
  ---------------------
  ErrorControl    0x1 (Normal)
  Group           Filter
  Start           0x4 (disabled)
  Type            0x1 (Kernel driver)

DLC System Driver Entries

The DLC subkey does not appear unless this service is installed. In Windows NT, the Data Link Control (DLC) protocol only needs to be installed on computers that access IBM mainframes (usually with 3270 applications) or on print servers that print directly to Hewlett-Packard printers. Network printers such as the HP III si use the DLC protocol, for example, because the frames received are easy to take apart.

The DLC driver depends on an having an NDIS group service available and is bound to the network adapter card through the NDIS device driver. Each adapter that supports the DLC protocol has a subkey under the DLC\Parameters subkey. With the Registry Editor, you can modify the following parameters for the DLC system driver. The path for these parameters is:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
        \DLC\Parameters\adapter name

   (time period) * DLC_TxTick_One * 40 milliseconds

   (time period - 5) * DLC_TxTick_Two * 40 milliseconds

DLC_T1_Tick_{One|Two}   REG_DWORD   1 to 255 milliseconds
   Specifies the delay before retransmitting an I frame if not
   acknowledged.
   Default: DLC_T1_Tick_One = 5; DLC_T1_Tick_Two = 25

DLC_T2_Tick_{One|Two}   REG_DWORD   1 to 255 milliseconds
   Specifies the delay before acknowledging frames in the receive
   window if the receive window has not been filled.
   Default: DLC_T2_Tick_One = 1; DLC_T2_Tick_Two = 10

DLC_Ti_Tick_{One|Two}   REG_DWORD   1 to 255 milliseconds
   Specifies the delay before testing an inactive station to determine
   if it is still active.
   Default: DLC_Ti_Tick_One = 25; DLC_Ti_Tick_Two = 125

Swap     REG_DWORD     0 or 1
   Used when talking over Ethernet to support certain Token
   Ring-to-Ethernet bridges in swapping of the Destination Address
   when using DLC over a Token Ring network. If this value is 0, the
   adapter addresses presented at the API interface are not
   bit-flipped before being put online. Default: 1

UseDixOverEthernet     REG_DWORD     0 or 1
   Specifies the default mode for the connection-oriented and
   connectionless 802.2 LLC (Logical Link Control) frames sent on
   Ethernet. If this value is 1, the DLC driver users DIX encoding in
   the frames to be transmitted instead of the 802.3 Ethernet format.
   Default: 0

Reference: "The Windows NT Resource Kit for Operating System Version 3.1."