HP OpenVMS Systems Documentation

When the database reaches the node limit, no more nodes are added to the database when your local node receives service announcement messages. You can ensure that the node limit is not reached by using the /USER_GROUPS qualifier to restrict access from the local node to other service nodes on the network.

If you do not specify either the /NODE_LIMIT=value or /NONODE_LIMIT qualifier, the default is no limit. A value of 0 indicates no limit.

/QUEUE_LIMIT=value

/RETRANSMIT_LIMIT[=count]

Use this qualifier only if your node allows outgoing connections (/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).

Specify a value in the range of 4 to 120. The default is 8. The value you choose depends on the type of physical link used for your network, as well as the amount of traffic on the network. See your network manager for a suggested value. You cannot change this value if active or pending connections exist.

/SERVICE_RESPONDER

/NOSERVICE_RESPONDER

If you specify /SERVICE_RESPONDER, your system responds to the special LAT multicast messages. (If you specify /NOSERVICE_RESPONDER, your system does not respond to those messages.) Compaq recommends that you set up only one or two nodes in the LAN as service responder nodes. The nodes should have the largest databases in the LAN. Use this option only if your node allows outgoing connections (/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).

If you do not specify either the /SERVICE_RESPONDER or /NOSERVICE_RESPONDER qualifier, the default is that your system will not respond to the special LAT multicast messages.

/SESSION_LIMIT=option

The options for the /SESSION_LIMIT qualifier are:

• A high limit allows users to have more sessions but increases memory utilization on your local node.
• A low limit decreases memory utilization on your local node but limits user access to services on the network.

If the limit is reached, interactive users cannot create new sessions. In this case, increase the session limit or disconnect any connections that are no longer being used.

Specify a value in the range of 0 to 255. Specifying 0 leaves no limit on the number of sessions that can be created. To prevent sessions from being created, use the /CONNECTIONS qualifier.

Not specify the /SESSION_LIMIT qualifier causes no limit on the number of incoming and outgoing sessions. This is the default.

/STATE=option

If you do not specify the /STATE=option qualifier, the default is that the LAT port driver and LAT protocol software on your node will be started (ON).

/UNIT_NUMBER_MAXIMUM=value

Also note the following points:

• When LATCP reaches the maximum unit number, it will continue to implicitly create LTA devices beginning with the lowest available unit number.
• You cannot use the System Generation utility (SYSGEN) to set the maximum unit number for a LAT device.

The range of maximum unit numbers is 99 to 9999. The default is 9999. Note that each time you specify the /UNIT_NUMBER_MAXIMUM qualifier, the LTA device seed value is reset to approximately half of the newly specified maximum unit number.

/USER_GROUPS=option[,...]

This qualifier affects your local node when outgoing connections are enabled (/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).

Use the SHOW NODE command for a list of the user groups (service groups) enabled for your node.

The /USER_GROUPS qualifier has several options. For each option described here, you can use two ways to specify more than one group:

• List them separated by commas.
• Specify a range.

The available options are as follows:

Description

The SET NODE command, which is typically executed in the site-specific LAT configuration command procedure, LAT$SYSTARTUP.COM, allows you to specify such characteristics as:

• Node name
• Node identification
• Service and user groups
• Timing of service announcements
• The maximum number of LAT sessions allowed simultaneously on the node
• The maximum number of outgoing sessions and incoming interactive sessions

Because LATCP commands change characteristics dynamically (that is, the commands take effect immediately), you can use the SET NODE command any time the LAT port driver is active. These changes remain in effect until the LAT port driver stops. To make sure the changes take effect when you start the LAT port driver again, edit LAT$SYSTARTUP.COM to include these changes. Start the LAT port driver by invoking LAT$SYSTARTUP.COM. (Refer to the OpenVMS System Manager's Manual.) The OpenVMS System Manager's Manual contains additional information about the LAT network in general and service nodes in particular.

Note The SET NODE command must be executed first (after LTDRIVER is loaded and the LATACP is started) to ensure that other management commands execute properly thereafter.

Examples

LATCP> SET NODE DUKE /IDENT="NODE DUKE, SALES VMSCLUSTER"
      

This command specifies node name DUKE for your local node. The identification string "NODE DUKE, SALES VMSCLUSTER" is multicast from node DUKE.

LATCP> SET NODE /MULTICAST_TIMER=50 /GROUPS=(ENABLE=(1-3,8,11),DISABLE=5)
      

This command causes your local node to send multicast messages every 50 seconds to announce DUKE's services to terminal servers. The command also enables groups 1, 2, 3, 8, and 11 for access to the local node, and it disables group 5 from accessing the local node. Group 5 had been previously enabled.

LATCP> SET NODE /CONNECTIONS=BOTH /USER_GROUPS=(ENABLE=(24,121-127),DISABLE=0)
      

This command sets up your local node to allow both incoming and outgoing connections. Users on your local node can access those service nodes belonging to user groups 24 and 121 through 127. Users cannot access service nodes in user group 0.

LATCP> SET NODE /CIRCUIT_TIMER=80 /KEEPALIVE_TIMER=20 -
_LATCP> /RETRANSMIT_LIMIT=20 /CONNECTIONS=BOTH /MULTICAST_TIMER=60-
_LATCP> /GROUPS=(DISABLE=0,ENABLE=73) /SESSION_LIMIT=(OUTGOING=10,INCOMING=0)
      

This command sets many characteristics at once for node DUKE.

Associates a logical port on the local node with a remote port on a terminal server that supports a device. Alternatively, it associates a logical port on the local node with a specific service. The service can be offered by a terminal server or associated with one or more dedicated ports on a remote LAT service node.

You must have OPER privilege to use this command.

Format

SET PORT port-name

Parameter

port-name

Specifies the name of the port. A port name must be in the form LTAn:, where n is a unique number from 1 to 9999.

Note You cannot use the CREATE PORT and SET PORT commands, along with the DCL command SET TERMINAL, to change the characteristics of a DECserver port unless there is an existing LAT connection to that DECserver.

Qualifiers

/APPLICATION

Specifies that a port on the local node is an application port, logically associated with a port on a terminal server or a dedicated port on another LAT service node. The terminal server port supports a device (for example, a printer). If the port is used to support a printer, the print queue is established in a startup command procedure. Refer to the OpenVMS System Manager's Manual for a description of configuring remote printers on a terminal server.

If you do not specify a port type, the default port type is APPLICATION.

/DEDICATED

Specifies that a logical port on your local node is dedicated to an application service. The /DEDICATED qualifier requires the /SERVICE qualifier.

To set up an application service for a logical port on a LAT service node:

1. Create the service by specifying the CREATE SERVICE/APPLICATION command and then define the dedicated port by specifying the CREATE PORT/DEDICATED command. You can include these commands in LAT$SYSTARTUP.COM.
2. Associate the dedicated ports with the service by specifying the SET PORT/DEDICATED/SERVICE command.
3. Start the application program. Within the program, allocate dedicated ports with the same name as those defined in LAT$SYSTARTUP.COM.

/LIMITED

Specifies that a logical port on your local node is limited to a service in the same way a port created using the /DEDICATED qualifier is dedicated to an application service. The difference is that ports created using the /LIMITED qualifier are under the control of the system login image (LOGINOUT.EXE) instead of an application program (a user who connects to a limited service and is assigned to a limited port receives the Username: prompt).

Using the /LIMITED qualifier, you can create a limited number of ports and map them to a specific service offered by the host system. If users are logged in to all of the limited ports for the service, no more connections are allowed to that service (terminal server users receive a "service in use" message).

/LOG

/NOLOG (default)

Specifies whether LATCP displays a message confirming that the port's characteristics were modified. If you do not specify the /LOG or /NOLOG qualifier, the default is that no message will be displayed.

/NODE=remote-node-name

Specifies the name of a terminal server (or a remote node that supports outgoing connections) to be logically associated with the specified application port on your node. The server supports a remote device. Note that you can set up an application port on your local node and associate the port with a dedicated port on a remote LAT service node. The remote port is dedicated to an application service.

/PASSWORD=remote-password

Specifies the password required to access a remote service that is logically associated with the specified application port.

/PORT=remote-port-name

Specifies the name of the remote port on a terminal server that supports a remote device, or specifies the name of a remote port dedicated to an application service on a remote LAT service node. In either case, the remote port is logically associated with the specified application port on your local node.

/QUEUED

/NOQUEUED

Specifies queued or nonqueued access to the server port. A queued or nonqueued request is accepted by a terminal server if a remote port is free. If the remote port is busy and queuing is enabled on the terminal server, then the server queues the remote request. If you do not want your remote requests to be queued on the server, specify /NOQUEUED.

Not specifying either the /QUEUED or /NOQUEUED qualifier results in queued access to the server port. This is the default.

/SERVICE=service-name

Specifies either of the following names:

• The name of the remote service offered at a terminal server port that will be associated with the specified application port (/APPLICATION) on the local node
• A service name for an application program being offered on a dedicated port (/DEDICATED) on a LAT service node

To specify the name of a remote service offered at a terminal server port, use the /NODE and /SERVICE qualifiers. To specify a particular port for a service, use the /NODE, /PORT, and /SERVICE qualifiers. Ask the terminal server manager for these names.

To name a service for a particular application program to be offered locally on a dedicated port, use the /DEDICATED and /SERVICE qualifiers. (The service must have been created with the CREATE SERVICE command.) Assign only one service to a dedicated port, but note that several ports can have the same service assigned.

Description

The SET PORT command associates an application port on your local node with a port or service on a terminal server.

To create a port, use one of the following methods:

• Interactively enter the CREATE PORT command.
• Run a program that creates ports.

When you associate an application port with a service on a terminal server, you allow access to any of the ports (printers) represented by that service (see Examples 1 and 2). Note that the application port must have been created with the CREATE PORT/APPLICATION command.

The SET PORT command can also associate a dedicated port on the local node with an application service offered locally. The service must already exist (see Example 3). Note that you must use the /DEDICATED and /SERVICE qualifiers.

The SET PORT command can also associate an application port on your local node with an application service associated with one or more dedicated ports on a remote LAT service node. This service is offered to users on terminal servers or on nodes that support outgoing connections (see Example 4). Note that the dedicated port must have been created with the CREATE PORT/DEDICATED command.

You can also set up the port as a limited port, using the /LIMITED qualifier.

Examples

See the examples for the SHOW PORT command for displays that reflect the changes made by the following SET PORT command examples.

LATCP> SET PORT LTA22: /APPLICATION /NODE=TS33EW /PORT=LN02
      

This command sets up port LTA22: as an application port to be associated with the port named LN02 on the terminal server named TS33EW. This command associates port LTA22: with a specific printer on the server. In the next example, the SET PORT command associates a port with a set of printers (designated by the service name PRINTER) on a terminal server.

LATCP> SET PORT LTA19: /APPLICATION /NODE=TLAT1 /SERVICE=PRINTER /QUEUED
      

This command shows how to associate a local logical port with a service (several printers) on a terminal server. The command associates the application port LTA19: with the service PRINTER on terminal server TLAT1. The service PRINTER can be associated with one or more ports on TLAT1. The /QUEUED qualifier specifies that the server offering the service PRINTER can queue the remote connection request if all ports offering the service are in use. Refer to the description of print operations in the OpenVMS System Manager's Manual for information about setting up print queues.

LATCP> SET PORT LTA21: /DEDICATED /SERVICE=GRAPHICS
      

This command specifies that the application port LTA21: on the local service node offers the service GRAPHICS to users on terminal servers or on nodes that support outgoing connections. GRAPHICS is a particular utility or application program.

LATCP> SET PORT MAIL_PORT /SERVICE=MAIL/NODE=RMNODE
      

This command associates the port whose logical name is MAIL_PORT with the dedicated service MAIL on remote node RMNODE. The port logically named MAIL_PORT was created with the CREATE PORT command (see Example 3 in the discussion of the CREATE PORT command). The logical name could also have been created with the DCL command ASSIGN or DEFINE. On node RMNODE, a port must be dedicated to the service MAIL by using the SET PORT port-name /DEDICATED/SERVICE=MAIL command.

$ LCP :== $LATCP
$ LCP CREATE SERVICE/LIMITED ONLY_ONE
$ (U>(LCP CREATE PORT/LIMITED LTA1234:)
$ (U>(LCP SET PORT LTA1234: /SERVICE=ONLY_ONE)
      

This series of commands, which includes the SET PORT command, creates a limited service that allows only one user to log in to the system through that service. When a user connects to service ONLY_ONE by responding to the terminal server prompt (Local>), the user is assigned port LTA1234 and then prompted for the user name. Any user who attempts to connect to the same service while LTA1234 has a user logged in receives the "service in use" message.