Appendix A - RAS Registry Values

When you install the Remote Access Service on a Windows NT Server computer, the Setup program adds the Remote Access key to the Windows NT Registry. The Remote Access key and its subkeys contain parameters specific to Remote Access.

This appendix tells you how to modify Remote Access parameters in the Registry.

Modifying the Registry

The Remote Access Setup program adds Remote Access keys to the Windows NT Registry.

Remote Access generally supplies good default values for RAS parameters, which you normally do not need to override. Still, for some systems, you might want to adjust individual parameters to suit your particular needs.

There are several sets of parameters you can modify or add. To override their defaults, add or change the appropriate key in the Registry. You can find these keys on the paths indicated in each section below.

To edit the Registry 

1. In the Start menu, click Run. 

2. In the Open box, type regedt32.

This command can also be run from the Command Prompt.

For detailed information on how to add a parameter to a key in the Registry, see online Help for the Windows NT Registry editor.

RemoteAccess Parameters

The default values of these parameters work well for all Windows NT operations.

The Parameters subkey for RemoteAccess has the following Registry path:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \RemoteAccess \Parameters.

AuthenticateRetries REG_DWORD 0 to 10  Sets the maximum number of unsuccessful retries that are allowed if the initial attempt at authentication fails. Default: 2. AuthenticateTime REG_DWORD 20–600 seconds Sets the maximum time limit, in seconds, within which a user must be successfully authenticated. If the client does not complete the authentication process within this time, the user is disconnected. Default: 120 seconds. AutoDisconnect REG_DWORD 0–1000 minutes Sets the time interval after which inactive connections are terminated. Inactivity is measured by lack of NetBIOS session data transfer, such as copying files, accessing network resources, and sending and receiving electronic mail. You might want to set this parameter to 0 minutes if clients are running NetBIOS datagram applications. Setting this parameter to 0 turns off AutoDisconnect. Default: 20 minutes. CallbackTime REG_DWORD 2–12 seconds Sets the time interval that the server waits before calling the client back when the Callback feature has been set. Each client communicates the value of its own callback time when connecting to a Remote Access server. This value can be found in the Modem.inf file for the client. If this value is not communicated (that is, if the client does not communicate a value for the callback time, as with Remote Access version 1.0 and 1.1 clients), then the value of the CallbackTime parameter becomes the default. Default: 2 seconds. EnableAudit REG_DWORD 0–1 Determines whether Remote Access auditing is turned on or off. If this feature is enabled, all audits are recorded in the Windows NT event log. You can see these audits in the Windows NT Event Viewer. Default: 1 (enabled). NetbiosGatewayEnabled REG_DWORD 0–1 Makes the server function like a NetBIOS gateway, allowing clients to access the LAN. If disabled, remote clients can access only the resources on the Remote Access server in a point-to-point connection; dial-in users cannot see the network or access network resources. This parameter should never be modified directly. Use RAS Setup to modify this parameter because RAS Setup also modifies bindings when changing this parameter. Default: 1 (enabled).

NetbiosGateway Parameters

The Registry path for these entries is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \RemoteAccess \Parameters \NetbiosGateway

DisableMcastFwdWhenSessionTraffic REG_DWORD 0–1  Allows NetBIOS session traffic (for example, Windows NT–based applications) to take priority over multicast datagrams (such as server messages). In other words, multicast datagrams are transferred only when there is no session traffic. Unless you're using an application that depends on multicast datagrams, leave this parameter enabled. Default: 1 (enabled). EnableBroadcast REG_DWORD 0–1 Determines whether broadcast datagrams are forwarded to remote computers. Broadcast datagrams are not often useful and take up too much bandwidth on a slow link. Unless you're using an application that relies on broadcast datagrams, leave this parameter disabled. Default: 0 (disabled). See also MultiCastForwardRate. EnableNetbiosSessionsAuditing REG_DWORD 0–1 Turns on and off Remote Access auditing of the establishment of NetBIOS sessions between the remote clients and the Windows NT servers. Turning this parameter on helps the administrator track the NetBIOS resources accessed on the LAN. Default: 0 (disabled). MaxBcastDgBuffered REG_DWORD 16–255 Sets the number of broadcast datagrams that the gateway buffers for a client. If you're using an application that communicates extensively through multicast or broadcast datagrams, then increase this parameter so that the Remote Access server can deliver all datagrams reliably. Default: 32. MaxDgBufferedPerGroupName REG_DWORD 1–255 Sets the number of datagrams that can be buffered per group name. Increasing this value buffers more datagrams per group name but also takes up more virtual memory. Default: 10. MaxDynMem REG_DWORD 131072– 4294967295 Sets the amount of virtual memory used to buffer NetBIOS session data for each remote client.

Note Because the Remote Access server is a gateway between the slow line and the LAN, data is stored (buffered) in its memory when coming from the fast line (LAN) before it is forwarded to the slow line (asynchronous line).

The Remote Access server minimizes the usage of the system's physical memory by locking only a minimal set of pages (about 64K per client) and making use of virtual memory (up to MaxDynMem) to buffer the rest of the data.

So, as long as you have space on your hard disk to expand Pagefile.sys, you can increase this parameter if needed.

You might have problems if you have an application with a LAN (fast) sender and an asynchronous (slow) receiver, and if the sender is sending more data than the Remote Access server can buffer in MaxDynMem. The Remote Access server tries to apply a form of NetBIOS level flow control by not submitting Ncb.receive on the session until it has enough buffer space to get incoming data.

For this reason, if you have such an application, you should increase your NetBIOS SEND/RECEIVE time-outs on the application server so that it waits for all data to be transmitted over the slow link to the remote client.

Default: 655350. MaxNames REG_DWORD 1–255 Sets the number of unique NetBIOS names each client can have, with a limit of 255 names for all clients together.

Note Remote clients running Windows NT and Windows for Workgroups might need as many as seven or eight names each. To accommodate these computers, make sure MaxNames is set to 8 or greater. If you have Windows NT or Windows for Workgroups clients dialing in to servers running Remote Access version 1.1 or earlier, set this parameter to 8 or greater.

Default: 255. MaxSessions REG_DWORD 1 – 255 Sets the maximum number of simultaneous NetBIOS sessions each client can have, with a limit of 255 sessions for all clients together. If you have multiple clients connecting simultaneously with each running 4 or 5 sessions, decrease the value of this parameter so that the total number of sessions does not exceed 255. Default: 255. MultiCastForwardRate REG_DWORD – 1 (disabled), 0 – 32,767 seconds Governs the multicasting of group name datagrams to all remote computers. This parameter filters datagrams sent on group names by forwarding them at a time interval specified by the parameter. Default: 5. The value –1 disables forwarding. The value 0 guarantees delivery of group name datagrams. The value n forwards datagrams every n seconds, where 1<= n <=32,767. If the EnableBroadcast parameter is set to 0, then broadcasts are not forwarded even if the MultiCastForwardRate parameter is set to a positive number (in this case, only multicast datagrams are forwarded). If MultiCastForwardRate is set to -1, broadcasts are still not forwarded even if EnableBroadcast is set to 1. See also EnableBroadcast. To save bandwidth for session traffic, you should filter the datagrams. However, if you have an application based on multicast datagrams, set this parameter to 0. Setting it to 0 guarantees delivery of all datagrams sent on group names from the LAN to the remote client. NumRecvQueryIndications REG_DWORD 1-32 Allows a Remote Access client to initiate multiple network connections simultaneously. If a remote client is running a NetBIOS application that does multiple NCB.CALL commands simultaneously, increase this parameter to improve performance. Default: 3. RcvDgSubmittedPerGroupName REG_DWORD 1–32 Determines the number of NetBIOS commands of the type Receive Datagram that can be submitted simultaneously per group name on the LAN stack. Keep this setting as small as possible to minimize the amount of memory consumed by system resources. Each datagram command received locks about 1.5K of physical memory in the system. Default: 3. RemoteListen REG_DWORD 0–2 Sets the level of access that a LAN client has to a remote client's resources. This is done by posting NCB.LISTEN commands on the NetBIOS names of the client.

Note It is best to leave the RemoteListen parameter set to the default, 1 (messages).

Allowing NCB.LISTEN capability on remote clients can significantly drain system resources and therefore is not recommended. If the RemoteListen parameter is configured to 2, Remote Access posts an NCB.LISTEN on all NetBIOS names of Remote Access clients. Considering that the average Windows NT client has about 7 or 8 NetBIOS names assigned to it, the total number of NetBIOS names for which an NCB.LISTEN would be posted is 7 or 8 * 256 (the maximum number of clients per Remote Access server).

Default: 1 (messages). SizWorkBufs REG_DWORD 1024–65536 Sets the size of work buffers. The default setting is optimized for the server message block (SMB) protocol, the protocol between the client and the server running Windows NT Server. Default: 4500.

IP Parameters

The Registry path for these entries is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \RemoteAccess
\Parameters\IP

WINSNameServer REG_SZ IP Address  Change this parameter in a RAS server's Registry to override the automatic assignment of the RAS server's WINS server to the RAS client. This parameter appears in the Registry only during an active connection to a RAS server. WINSNameServerBackup REG_SZ IP Address Add this parameter to a RAS server's Registry to override the automatic assignment of the RAS server's backup WINS server to the RAS client. This parameter appears in the Registry only during an active connection to a RAS server. WIDNSNameServers REG_MULTI_SZ IP Addresses Add this parameter to a RAS server's Registry to override the automatic assignment of the RAS server's DNS servers to the RAS client. This parameter appears in the Registry only during an active connection to a RAS server.

AsyncMac Parameters

The Registry path for these entries is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services
\AsyncMacn\Parameters

MaxFrameSize REG_DWORD 576–1514  Determines the maximum frame size. Use smaller frames for noisy links. A lower setting sends less data per frame, slowing performance. Do not change this parameter for previous versions of the Remote Access Service. The value is negotiated between the server and Windows NT clients. Default: 1514. TimeoutBase REG_DWORD 500–1000 Determines the amount of time that elapses on a NetBIOS gateway before a connection is disconnected. If you are experiencing an abnormal number of time-out errors using the NetBIOS gateway (more than 10 time-outs per 100 kilobytes received), increase the TimeoutBase value from 500 to 1000 if your computer has a security device or your computer's modems have hardware compression or error control enabled. With TimeoutBase increased to 1000, network functionality may on very rare occasions act abnormally. For example, you might have to type network commands more than once, or functionality may periodically slow down. Default: 500.

NdisWan Parameter

The Registry path for this entry is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services
\NdisWan\Parameters

NetworkAddress=" xxxxxx " REG_SZ   Network address  Add this parameter to reassign the first 4 bytes of the 6-byte IEEE address. For example, if you reset the address to "03-1F-2C-81-92-34", only the first 4 bytes are looked at. The last 2 bytes are reserved to uniquely identify the port. Reset this parameter in the NdisWan\Parameters key with the datatype REG_SZ.

NwlnkRip Parameters

The Registry path for these entries is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \NwlnkRip \Parameters

NetbiosRouting REG_DWORD Range: 0, 2, 4, or 6 Controls the forwarding of IPX NetBIOS broadcast packets to and from the LAN. The RAS server can forward NetBIOS broadcast packets (IPX type-20) between RAS clients and the local network. Set to 2, this parameter enables forwarding of NetBIOS broadcast packets from the remote client to the LAN. Set to 4, this parameter enables forwarding of NetBIOS broadcast packets from the LAN to the remote client. Set to 6, this parameter enables two-way forwarding of NetBIOS packets between remote clients and the LAN. You may also need to set the DisableDialinNetbios registry entry, depending on your IPX NetBIOS application configuration. See the "NwlnkIpx Parameters" section for more information. Default: 2.

RasMan Parameters

The Registry path for this entry is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \RasMan \Parameters

Logging REG_DWORD 0 – 1  Sets logging of all communication from serial ports to the device connected to them during command mode. This parameter is useful for solving problems with serial devices and for testing new entries added to the Modem.inf or Pad.inf files. Because some of the information will not be printable characters, you might want to view the Device.log file in a text editor that can display both character and hexadecimal output. Also, Device.log contains a carriage return and line feed at the end of each line. These bytes are provided by the program that creates the Device.log file and do not represent information communicated from or to the device. Set to 1, communication from the serial port to the device connected to it will be logged in the file \systemroot\system32\ras\device.log. Logging is suspended after successful connection to the remote device and transmission of data. Logging resumes when a new connection is established and is appended to Device.log until the file size exceeds approximately 100K. Device.log is then cleared and logging resumes. Device.log is also cleared when any RAS component is started after all RAS components have been stopped. Default: 0.

PPP Parameters

The Registry path for these entries is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \RasMan \PPP

MaxTerminate REG_DWORD 0 – unlimited  Sets the number of Terminate-Request packets sent without receiving a Terminate-Ack before assuming that the peer is unable to respond. Default: 2. MaxConfigure REG_DWORD 0 – unlimited Sets the number of Configure-Request packets sent without receiving a valid Configure-Ack, Configure-Nak, or Configure-Reject before assuming that the peer is unable to respond. Default: 10. MaxFailure REG_DWORD 0 – unlimited Sets the number of Configure-Nak packets sent without sending a Configure-Ack before assuming that the configuration is not converging. Default: 10. MaxReject REG_DWORD 0 – unlimited Sets the number of Config-Rejects sent before assuming that the PPP negotiation will not converge. Default: 5. RestartTimer REG_DWORD 0 – unlimited Sets the time (in seconds) available for transmission of Configure-Request and Terminate-Request packets. Expiration of the Restart timer causes a time-out event, and retransmission of the corresponding Configure-Request or Terminate-Request packet. Default: 3. NegotiateTime REG_DWORD 0 – unlimited Sets the amount of time allowed (in seconds) for PPP negotiation to converge successfully before disconnecting the line. 0 means that the line will never be hung up. Default: 150. ForceEncryptedPassword REG_DWORD 0 – 1 Used on RAS servers only. Sets the use of the Crypto-Handshake Authentication Protocol (CHAP) while authenticating clients. Set to 1, the server will use CHAP during authentication. Set to 0, the server will negotiate PAP. Default: 1. Logging REG_DWORD 0 – 1 Sets logging of PPP events. Set to 1, all PPP events will be logged in the file \systemroot\system32\ras\ppp.log. This parameter is useful for solving problems with PPP connections. Default: 0. DisableSoftwareCompression REG_DWORD 0 – 1 Enables or disables software compression. Set to 1, software compression is disabled. Set to 0, software compression is enabled. Default: 0.

PPP Subkeys

The following entries are subkeys to the PPP key:

CBCP REG_EXPAND_SZ DLL Path  Specifies the location of the Callback Control Protocol (CBCP) DLL. CBCP negotiates callback information with the remote client. Always present. CHAP REG_EXPAND_SZ DLL Path Specifies the location of the Crypto-Handshake Authentication Protocol (CHAP) DLL. Always present. COMPCP REG_EXPAND_SZ DLL Path Specifies the location of the Compression Control Protocol (CCP) DLL. CCP negotiates compression with the remote client. Always present. IPCP REG_EXPAND_SZ DLL Path Specifies the location of the Internet Protocol Control Protocol (IPCP) DLL. Present if RAS is configured to use TCP/IP and TCP/IP is installed. These parameters can be added to the IPCP subkey: AcceptVJCompression REG_DWORD Range: 0 - 1 Add this parameter to prevent IPCP from accepting IPCP standard option 0x02, Van Jacobson header compression. If this parameter has not been added or is set to 1, RAS clients will accept VJ compression. Default: not in registry PriorityBasedOnSubNetwork REG_DWORD Range: 0 - 1 A computer can connect to the LAN using a network card and a RAS connection. If the RAS connection and the LAN network adapter card are assigned addresses with the same network number and the Use Default Gateway On Remote Network checkbox is selected, then all packets will be sent over the RAS connection, though the two addresses are in different subnetworks within the same network. Set this parameter to 1 to send packets over the network card. For example, if the network adapter card has IP address 10.1.1.1 (subnet mask 255.255.0.0) and the RAS connection is assigned the address 10.2.1.1, RAS will send all 10.x.x.x packets using the RAS connection. If the parameter is set, RAS will send 10.2.x.x packets using the RAS connection and 10.1.x.x packets using the network adapter card. Default: not in registry RequestNameServerAddresses REG_DWORD Range: 0 - 1 Add this parameter on RAS clients to prevent IPCP from requesting the Microsoft extension options for WINS and DNS server address negotiation, i.e. IPCP options 0x81, 0x82, 0x83, 0x84. If this parameter has not been added or is set to 1, the client-side will request the addresses. Default: not in registry RequestVJCompression REG_DWORD Range: 0 - 1 Add this parameter on RAS clients to prevent IPCP from requesting IPCP standard option 0x02, Van Jacobson header compression. If this parameter has not been added or is set to 1, RAS clients will request VJ compression. Default: not in registry IPXCPv REG_EXPAND_SZ DLL Path Specifies the location of the Internetwork Packet Exchange Control Protocol (IPXCP) DLL. Present if RAS is configured to use IPX and the Client Service for NetWare or Gateway Service for NetWare is installed. NBFCP REG_EXPAND_SZ DLL Path Specifies the location of the NetBEUI Framing Control Protocol (NBFCP) DLL. Present if RAS is configured to use NetBEUI and NetBEUI is installed. PAP REG_EXPAND_SZ DLL Path Specifies the location of the Password Authentication Protocol (PAP) DLL. Always present.

Rdr Parameters

The Registry path for this entry is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \Rdr \Parameters

RawIoTimeLimit REG_DWORD see below  This parameter applies only to configurations using the NetBIOS gateway. Sets the redirector to send data in 64 kilobyte blocks. When RawIoTimeLimit turned on, throughput increases by 10-15 percent. All other simultaneous data transfers are blocked when communicating at this speed. This parameter is turned off for slow links and on for faster links, by default. For example, if you are communicating at 14,400 bps or slower, this feature is turned off. If you are communicating at faster speeds, such as through an ISDN line, this feature is turned on. The following list shows what values turn raw I/O on and off for ISDN connections: RawIoTimeLimit set to 9: Raw I/O is enabled when connected through one 64K channel. Raw I/O is enabled when connected through two 64K channels. RawIoTimeLimit set to 5 (default): Raw I/O is disabled when connected through one 64K channel. Raw I/O is enabled when connected through two 64K channels. RawIoTimeLimit set to 0: Raw I/O is disabled when connected through one 64K channel.Raw I/O is disabled when connected through two 64K channels.

RasArp Parameters

The Registry path for this entry is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \RasArp \Parameters

FilterBroadcasts REG_DWORD Range: 0 - 1 Add this parameter to cause RAS to transmit broadcast packets (for example, destination IP address 255.255.255.255) and subnet multicasts (for example, destination IP address 11.101.255.255). Set this parameter to 0 on clients if the computer is calling into third-party remote access routers that support broadcast/multicast forwarding. (Windows NT Remote Access servers do not forward broadcasts or multicasts.) Default: 1.

Nbf Parameters

The Registry path for this entry is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \Nbf \Parameters

InitUIFrames REG_DWORD Range: 0 - unlimited Add this parameter to set the number of NetBIOS names that can be added to the network simultaneously from a RAS client. Default: 5.

NwlnkIpx Parameters

The Registry path for these entries is the following:

HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \NwlnkIpx \Parameters

DisableDialinNetbios REG_DWORD Range: 0 - 3 Controls the forwarding of IPX type 20 packets between the remote RAS client, the LAN (by means of the RAS IPX router) and the RAS server running an IPX NetBIOS application (internal net). This parameter controls only dial-in lines on RAS servers. Set to 0, IPX type 20 packets will broadcast from the RAS server to remote clients and from the remote clients to the RAS server then through the IPX router for broadcast on the LAN (if the router is configured to forward IPX NetBIOS packets. Set to 1 (default), IPX type 20 packets will broadcast only from remote clients to the internal net and to the RAS IPX router. This setting disables broadcasts from the internal net to the remote clients. Set to 2, IPX type 20 packets will broadcast from the internal net to the remote clients. Set to 3, all IPX type 20 broadcasts are disabled. You might also need to set the NetbiosRouting registry entry, depending on your IPX NetBIOS application configuration. See the "NwlnkRip Parameters"section for more information. Default: 1.