VTAM-relevant columns of the SYSIBM.LUNAMES table

The LUNAMES table defines the security and mode requirements for conversations with other systems. Decisions about how to populate this table depend on how you intend to use DB2®.

  • If you use this system only as a server, DB2 can use a blank in the LUNAME column as a default. DB2 uses the values in the default row as defaults for LUs that are not explicitly defined in LUNAMES. If you do not have a row with a blank in the LUNAME column, DB2 rejects client connections that do not explicitly state a valid LUNAME. The DSNTIJSG installation job creates the default row in table SYSIBM.LUNAMES.
  • If this DB2 requests data from other systems, you need to provide LU names for those systems.If the remote LU exists in the same VTAM® domain, specify the APPL name, not the ACBNAME.

The LUNAMES table has the following columns:

LUNAME CHAR(8)
The LU name of the remote system. The default of 8 blanks indicates that this row is used for serving the requests of any system that is not specifically listed in the LUNAMES table. For example, because USIBMSTODB21 acts strictly as a server for many Windows requesters, Spiffy leaves the LUNAME column blank for those requesters and uses default values for the entire row.

However, you must provide LU names for any remote system that uses different values from the defaults.

SYSMODENAME CHAR(8)
This column is ignored for DRDA access conversations.
SECURITY_IN CHAR(1)
Defines the security options that are accepted by this DB2 subsystem when an SNA client connects to DB2. The default, A, means that an incoming connection request is accepted if it includes any of these:
  • A user ID
  • A user ID and password
  • A user ID and RACF® PassTicket
  • A Kerberos security ticket.
SECURITY_OUT CHAR(1)
Defines the security option that is used when local DB2 SQL applications connect to any remote server associated with this LUNAME. The default, A, means that outgoing connection requests contain an authorization ID without a password.
ENCRYPTPSWDS CHAR(1)
For now, Spiffy uses a blank to indicate no encryption of passwords.
MODESELECT CHAR(1)
Determines whether to use the default mode or to choose a mode from the MODESELECT table.Start of change Spiffy uses a blank to use the default IBMRDB mode for conversations using DRDA access. End of change
USERNAMES CHAR(1)
This column is used for inbound and outbound requests to control authorization ID translation.

Spiffy uses a blank to indicate that no authorization IDs are translated, and also that no passwords are sent to the server.

GENERIC CHAR(1)
A Y in this column indicates that a generic LU name is to be used for CNOS processing and SQL requests sent to the partner LU. A value of N or a blank indicates that the name specified in the LUNAME column is to be used.

Spiffy's USIBMSTODB21 location wants a LUNAMES table that looks like the following table.

Table 1. Spiffy's SYSIBM.LUNAMES table. The row of blanks is a default row that Spiffy intends to use for Windows requesters in its initial testing.
LUNAME SYSMODENAME USERSECURITY1 ENCRYPTPSWDS MODESELECT USERNAMES
LUDB21          
LUDB22          
LUSQLDS          
(blanks)          
Note:

1. USERSECURITY refers to SECURITY_IN AND SECURITY_OUT
Spiffy can use an SQL INSERT statement to add the appropriate rows. For example, they add the LU name for USIBMSTODB22 with this statement: 
INSERT INTO SYSIBM.LUNAMES (LUNAME)
  VALUES ('LUDB22');