1 CREATE2 LINK Creates the LAT data links, which are connections to LAN devices, such as Ethernet or FDDI (fiber distributed data interconnect) controllers, that you want your node to use. You must have OPER privilege to use this command. Format CREATE LINK link-name 3 Parameter link-name Specifies a name for a LAT data link. A link name can have up to 16 ASCII characters. The characters allowed are as follows: o Alphanumeric characters: A-Z, a-z, 0-9 o A subset of the international character set: ASCII codes 192- 253 o Punctuation characters: dollar sign ($), hyphen (-), period (.), and underscore (_) You can create a maximum of eight links on your local node. Use the SHOW LINK command for a list of the link names that are defined for your node. 3 Qualifiers /DECNET /DECNET /NODECNET Directs LAT protocol to use the DECnet data link address ( /DECNET) or the hardware address (/NODECNET) when starting the LAN controller. If you do not specify the /DECNET or /NODECNET qualifier, the default is that the LAT protocol will use the DECnet data link address. Note that if you enter the CREATE LINK command with the /DECNET qualifier and receive an error message indicating a "bad parameter value," it means the SCSSYSTEMID system parameter is set to an illegal value. To change the value of this parameter, use the following formula: (1024 * a) + n In the formula, a is the DECnet area and n is the DECnet computer number. If the value is outside the range of 1025 to 65535, the LAT protocol cannot start. When you use the /NODECNET qualifier, the LAN device driver code determines which address to use. For example: o If SCSSYSTEMID is set to 0 but DECnet is already running on an Ethernet controller, the LAN device code allows LAT to use the same address as DECnet (AA-00-04-00-xx-xx). o If SCSSYSTEMID is set to 0 and DECnet is not running, the 08- 00-2B-xx-xx-xx address is used (a different address format is used if your LAN controller is supplied by a vendor other than Digital). o If the setting for SCSSYSTEMID is the same as the DECnet node number and DECnet is not running, the LAN device code forces LAT to use the AA-00-04-00-xx-xx address. If DECnet is configured on the system (or if the system is part of a cluster), SCSSYSTEMID may contain a nonzero value. This is a problem only when the system has 2 or more LAN controllers connected to the same logical LAN. For example, if your system has an FDDI controller and an Ethernet controller, your site may be configured so that the FDDI ring attached to the FDDI controller and the Ethernet segment attached to the Ethernet controller are bridged by a 10/100 LAN bridge (FDDI-to-Ethernet). In this configuration, it is impossible to run LAT over both controllers. In such a configuration, you must run LAT and DECnet over the same controller if SCSSYSTEMID is not 0. If you fail to do so, DECnet starts first, which in turn causes the LAT startup on the other controller to fail. This failure occurs because LAT startup tries to use the AA-00-04-00-xx-xx address (the DECnet LAN address) but is prevented from doing so by the data link layer. The LAT startup fails because DECnet is already using this address on a different controller. (In a single logical LAN, all data link addresses must be unique. In this setup, both controllers try to use the same address, which is then not unique.) The following command (which creates the LAT link) also fails because the LAN driver tries to use the address based on SCSSYSTEMID: LATCP> CREATE LINK LAT$LINK_2 /NODECNET If SCSSYSTEMID is set to 0, configuring LAT and DECnet on different controllers is possible. However, in a cluster environment, SCSSYSTEMID cannot be set to 0. /DEVICE /DEVICE=device-name Specifies the LAN controller device name for a LAT data link (for example, XEB0:). Only one LAT data link can be associated with a LAN controller. If you enter the CREATE LINK command without the /DEVICE qualifier, LATCP attempts to find an available controller by using a list of possible LAT data link device names. Digital advises that you specify a default device name by defining the LAT$DEVICE logical name. /LOG /LOG /NOLOG Specifies whether LATCP displays a message confirming that the link was created. If you do not specify the /LOG or /NOLOG qualifier, the default is that no message will be displayed. /STATE /STATE=option Specifies whether the link will be available for use. STATE can have two options: ON Specifies that the created link will be available for use with the LAT protocol running. OFF Specifies that the created link will not be available for use. If you do not specify the /STATE=option qualifier, the default is that the created link will be available for use (ON). 3 Example LATCP> CREATE LINK NETWORK_A /DEVICE=XEB0: /STATE=ON The CREATE LINK command in this example creates an Ethernet link named NETWORK_A. It specifies the Ethernet controller device XEB0 for that link. The link will be available for use. 2 PORT Creates a logical port on your local node that connects with a remote device on a terminal server. Alternatively, this command creates a logical port on your local node that connects 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 CREATE PORT [port-name] 3 Parameter port-name Specifies the port name in the form LTAn:, where n is a unique number from 1 through 9999. If the port you specify already exists, LATCP returns the following error message: %LAT-W-CMDERROR, error reported by command executor -SYSTEM-F-DUPLNAM, duplicate name If you do not specify the port name, you must specify the /LOGICAL qualifier. NOTES When creating a port, note the following: o Digital recommends that you assign a logical name when creating a port, instead of specifying a specific LTA device. o 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. 3 Qualifiers /APPLICATION Specifies that a logical port on your node is an application port. It can be used to connect to a remote device (typically a printer) on a terminal server or to a dedicated port on another LAT service node. If you do not specify a port type, the default port type is APPLICATION. NOTE By default, LATCP creates application LAT devices with the HANGUP terminal characteristic. However, if you want to apply the NOHANGUP characteristic to application LAT devices, you can do so by entering specific LATCP and DCL commands. For example: $ LCP :== $LATCP $ LCP CREATE PORT LTA1234 $ LCP SET PORT LTA1234 /APPLICATION /NODE=terminal_server /PORT=server_port $ SET TERMINAL LTA1234 /PERMANENT /NOHANGUP Note that you can insert the SET TERMINAL command in the SYS$MANAGER:LAT$SYSTARTUP.COM file (enter the command for each LAT device that requires the NOHANGUP characteristic). /DEDICATED Specifies that a logical port on your local node is dedicated to an application service. When users on a terminal server (or on another node that supports outgoing connections) request a connection to this service name, they are connected to the dedicated port. See the OpenVMS I/O User's Reference Manual for a description of programming an application service. After creating a dedicated port on a node, use the SET PORT /SERVICE command to map this port to a service. /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 /LOG /NOLOG Specifies whether LATCP displays a message confirming that the port was created. If you do not specify the /LOG or /NOLOG qualifier, the default is that no message will be displayed. /LOGICAL /LOGICAL=(NAME=logical-name[,TABLE=table][,MODE=mode]) Specifies a logical name to be associated with the actual name of the created port. You must specify a logical name if you do not specify a port name. NOTE If you have sufficient privileges to create a port, but lack the privilege to assign a logical name, the port will still be created. You can specify one of the following options for the TABLE keyword: GROUP Places the logical name in the group logical name table. You must have GRPNAM or SYSPRV privilege to place the logical name in the group logical name table. JOB Places the logical name in the jobwide logical name table. PROCESS Places the logical name in the process logical name table. This is the default. SYSTEM Places the logical name in the system logical name table. You must have SYSNAM or SYSPRV privilege to place a name in the system logical name table. You can also specify the name of a specific table. For example, you could specify LNM$PROCESS, which would be the equivalent of specifying PROCESS. Options for the MODE keyword are: EXECUTIVE Creates an executive mode logical name. You must have SYSNAM privilege to create an executive mode logical name. SUPERVISOR Creates a supervisor mode logical name. USER Creates a user mode logical name. The access mode associated with the logical name is determined by maximizing the access mode of the caller with the access mode specified by the MODE keyword: the mode with the lower privilege is used. You cannot specify an access mode with a privilege higher than that of the table containing the logical name. However, if your process has SYSNAM privilege, then the specified access mode is associated with the logical name regardless of the access mode of the caller. If you omit the MODE keyword, the access mode of the caller is associated with the logical name. You can also create the port as a limited port, using the /LIMITED qualifier. 3 Examples 1.LATCP> CREATE PORT LTA22: /APPLICATION The CREATE PORT command in this example creates an application port named LTA22: on a service node. You can associate the port with a specific printer on a terminal server (use the SET PORT /NODE /PORT command) or with a set of printers on a terminal server (use the SET PORT /NODE /SERVICE command). Or, you can associate the port with a dedicated port on a remote service node. In this case, use the SET PORT /NODE /SERVICE command, where the /SERVICE qualifier specifies an application service associated with a dedicated port on the remote node. See the examples for the SET PORT command. 2.LATCP> CREATE PORT LTA21: /DEDICATED The CREATE PORT command in this example creates the LTA21: port. It will be used as a dedicated port that offers a specific service rather than a general timesharing service. 3.LATCP> CREATE PORT /LOG /APPLICATION - _LATCP> /LOGICAL=(NAME=MAIL_PORT, TABLE=PROCESS, MODE=SUPERVISOR) The CREATE PORT command in this example creates an application port. It assigns the name of the new port to the specified logical name (MAIL_PORT). The logical is created as a supervisor mode logical name in the LNM$PROCESS_TABLE logical name table. LATCP displays a confirmation message. 4.$ LCP :== $LATCP $ LCP CREATE SERVICE/LIMITED ONLY_ONE $ LCP CREATE PORT/LIMITED LTA1234: $ LCP SET PORT LTA1234: /SERVICE=ONLY_ONE This series of commands 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. 2 SERVICE Creates a service on a service node. You must have OPER privilege to use this command. Format CREATE SERVICE [service-name] 3 Parameter service-name Specifies a LAT service name. By default, a service name is the name of the local node you defined with the SET NODE command. The service name can be from 1 to 16 ASCII characters in length. The characters allowed are as follows: o Alphanumeric characters: A-Z, a-z, 0-9 o A subset of the international character set: ASCII codes 192- 253 o Punctuation characters: dollar sign ($), hyphen (-), period (.), and underscore (_) 3 Qualifiers /APPLICATION Specifies that the created service is an application service. An application service offers a specific application on the service node rather than a general interactive service. You can define a dedicated port for the service by using the CREATE PORT and SET PORT commands. /IDENTIFICATION /IDENTIFICATION[="identification-string"] Describes and identifies a service. Service nodes include the identification string in service announcements. A service node announces its services at regular intervals established with the SET NODE command. Entering the LATCP SHOW NODE command or the DECserver SHOW NODE command generates a display that includes this identification string. By default, the identification string is a translation of SYS$ANNOUNCE. You cannot specify more than 64 ASCII characters in an identification string (a SYS$ANNOUNCE longer than that will be truncated to the first 64 characters). Enclose the string in quotation marks ("). /LIMITED Specifies that the service is a limited service, using devices assigned the limited characteristic and associated with (mapped to) this limited service. This qualifier is used in conjunction with the SET PORT /LIMITED command (see example). /LOG /LOG /NOLOG Specifies whether LATCP displays a message confirming that the service was created. If you do not specify the /LOG or /NOLOG qualifier, the default is that no message will be displayed. /STATIC_RATING /STATIC_RATING=rating /NOSTATIC_RATING Enables or disables dynamic service ratings. A dynamic service rating means that a LAT algorithm calculates the availability of a service dynamically, based on the overall level of activity of the node that offers the service and the amount of memory. When a terminal server or node requests a connection to a service that is offered on two or more service nodes, the requesting node selects the service node with the highest (most favorable) service rating. This selection process is called load balancing. The dynamic service rating, which is the default, is usually adequate for efficient load balancing on the LAT network. However, when necessary, you can use the /STATIC_RATING qualifier to disable dynamic service ratings so that you can specify a static (fixed) rating. That static rating value does not change until the dynamic service rating is reenabled. Use the static rating to direct users away from or toward your node temporarily. Static ratings range from 0 to 255. Specify a low value to make the local service node less likely to be used; specify a high value to make the local service node more likely to be used. If you do not specify either the /STATIC_RATING or /NOSTATIC_ RATING qualifier, the default is that the LAT software uses the dynamic service rating. Limited and application services do not rely exclusively on the dynamically calculated service rating. Instead, they use a portion of the dynamic rating based on how many ports are available for the service. For example, if a limited service has 50% of its ports available, the dynamic service rating will be scaled, halved, and then added to 105. When ports are available, the rating will always be above the value 105. When all ports for a limited or application service are in use, the rating will be based on the scaled dynamic rating and the number of free queue slots on the local node. The rating will always be less then 90. This rating procedure for limited and application services follows the terminal server rating algorithm for services and available ports that the service offers, while at the same time taking into account the availability of the node (which is the factor used to calculate the dynamic rating). If your system is licensed for a specific number of units (where only a fixed number of users can log in to the system regardless of how the login limit is set), then all dynamic ratings become 0 when all OpenVMS license units have been consumed. (This forces all node service ratings to the lowest possible value when logins are not possible because all OpenVMS license units have been consumed.) Note as well that the LAT software transmits a service announcement message when a user logs in to or out of the system. This allows the system to more quickly provide information about service rating changes that result from a login or logout operation. 3 Examples 1.LATCP> CREATE SERVICE/STATIC_RATING=195 SALES The CREATE SERVICE command in this example creates the service SALES on a service node. This command assigns a static rating of 195 so terminal servers (and nodes that support outgoing connections) can assess the availability of services on the node. 2.LATCP> CREATE SERVICE/APPLICATION GRAPHICS This command creates the service GRAPHICS on the local node. Use the CREATE PORT/DEDICATED and SET PORT/SERVICE=GRAPHICS commands to create a port that is dedicated to this service. 3.$ LCP :== $LATCP $ LCP CREATE SERVICE/LIMITED ONLY_ONE $ LCP CREATE PORT/LIMITED LTA1234: $ LCP SET PORT LTA1234: /SERVICE=ONLY_ONE This series of commands 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.