Using NCP to Create and Tailor the Configuration Database

The system manager is responsible for configuring the node for network operation by supplying information in the DECnet for OpenVMS configuration database about the following network components:

• The local (executor) node

• Remote nodes with which the local node can communicate • Local circuits

• Local lines • Network objects • Network event logging

The configuration database is actually two databases: a permanent database that establishes the default parameter values for node startup, and a volatile database that contains the current parameter values.

You can use the Network Control Program (NCP) utility to build the network configuration database manually or to modify its contents. If you are configuring the node for the first time, you can use the automatic configuration command procedure, NETCONFIG.COM, to establish parameters needed to get DECnet running. The procedure for using NETCONFIG.COM is described in an earlier section. (See Section 3.3.2.2.)

When you run NCP and enter a command, NCP will prompt you for selected parameters if you do not supply them. NCP also provides a HELP facility with information about each command, which you can access as follows:

$ RUN SYS$SYSTEM:NCP NCP>HELP [topic...]

Refer to the DECnet for OpenVMS Network Management Utilities for a complete description of the NCP command language.

Use NCP SET commands to establish the contents of the volatile database, and DEFINE commands to establish the contents of the permanent database. You must have OPER privilege to change the volatile database and SYSPRV privilege to change the permanent database.

The permanent database information is supplied to the volatile database when the network is started (that is, the STARTNET.COM command procedure is executed). You can also use the ALL parameter with the SET command to cause all permanent database entries for a network component to be loaded into the volatile database.

The basic NCP commands required to define the network components in the permanent configuration database are shown in the following list. Some of these commands must be used multiple times, such as DEFINE EXECUTOR to define several parameters and DEFINE NODE to list all the nodes in the network.

$ RUN SYS$SYSTEM:NCP

NCP>DEFINE EXECUTOR executor-parameter [...] NCP>DEFINE NODE node-id

NCP>DEFINE CIRCUIT circuit-id NCP>DEFINE LINE line-id NCP>DEFINE OBJECT object-name NCP>DEFINE LOGGING MONITOR STATE ON

NCP>DEFINE LOGGING MONITOR EVENTS event-list NCP>EXIT

In an NCP command, node-id can be a node name a maximum of six

alphanumeric characters long, or a node address in the form area-number.node-

number, where the area number can be from 1 to 63 and the node number can

be from 1 to 1023. If no area number is specified, the area number of the executor node is used. The default area number for the executor is 1. The object-name can be up to 16 characters long.

The circuit-id and line-id values are in the form dev-c[-u], defined as follows:

dev A device name

c A decimal number (0 or a positive integer) designating a device’s hardware controller

u The unit number of the device name (0 or a positive integer); included if more than one unit is associated with the controller

Reference DECnet for OpenVMS Network Management Utilities for a list of device names.

For example, the circuit and line identification for an Ethernet SVA device is in the form SVA-c (such as SVA-0); an example for a QNA device is QNA-0. An example of a synchronous DDCMP device identifier is DSV-2, and an example of an asynchronous device identifier is TT-1-0.

NCP commands also recognize the plural forms of the network component names: KNOWN NODES, KNOWN CIRCUITS, KNOWN LINES, KNOWN OBJECTS.

To modify the current configuration of your node, you can issue SET commands for any network component. For example, to add circuit and line entries for the Ethernet UNA device (the DEUNA), specify the following commands:

$ RUN SYS$SYSTEM:NCP NCP>SET LINE UNA-0 STATE ON NCP>SET CIRCUIT UNA-0 STATE ON NCP>EXIT

To determine the contents of your network configuration database, use the NCP commands LIST and SHOW. The LIST command displays information in the permanent database; the SHOW command displays volatile database entries. (For more information on monitoring the network using the network databases, see Chapter 4.) To delete entries from the configuration database, use the PURGE and CLEAR commands. The PURGE command deletes permanent database entries; the CLEAR command deletes or resets volatile database entries. For example, to list the permanent name and address of a node, enter the following commands:

$ RUN SYS$SYSTEM:NCP NCP>LIST NODE node-id NCP>EXIT

To delete a node from the permanent database, enter the following commands:

$ RUN SYS$SYSTEM:NCP NCP>PURGE NODE node-id ALL NCP>EXIT

Node-id can be either the node name or the node address. You can also delete

an individual parameter for a node. For example, to purge the RECEIVE PASSWORD parameter for node PURPLE, enter the following commands:

$ RUN SYS$SYSTEM:NCP

NCP>PURGE NODE PURPLE RECEIVE PASSWORD NCP>EXIT

Because the PURGE command does not affect the volatile (memory-resident) copy of the DECnet database, you can access a node deleted with the PURGE command until DECnet is started again. If you use the CLEAR command to delete a node entry, the node entry will reappear in the volatile database after DECnet is started again.