Using the SNALINK LU6.2 subcommand

This section details how to use the LIST MODIFY subcommand for the MVS™ SNALINK LU6.2 address space. The SNALINK LU6.2 address space has interactive commands to control the operation and list the status of the active address space. The LIST MODIFY subcommand writes a report to the MVS system console giving the status of the specified connections.

The connection status listed by the LIST subcommand can be requested for a particular remote VTAM® application LU name or destination IP address. The following is an example using the LU parameter:

MODIFY procname,LIST LU=lu_name

In this example, procname is the member name of the cataloged procedure used to start the local SNALINK LU6.2 address space and lu_name is the remote VTAM application LU name of the connection for which you are requesting the status.

Figure 1 shows a sample output from the subcommand.

Figure 1. LIST MODIFY subcommand output example

f snal621a,list lu=snal622a                                 
EZA5971I LIST ACCEPTED; RANGE = SINGLE CONNECTION           
EZA5967I   9.67.22.2 (Connected on 01.051 at 15:44:32)      
EZA5968I     Connected via:  DATA            Trace Level: ON
EZA5969I     SEND:-  Status: Allocated       Packets Out: 1 
EZA5970I     RECV:-  Status: Allocated       Packets In:  1 
EZA5974I LIST COMPLETED

An active connection displays the EZA5968I Connected message with the Allocated status for both the send and receive conversations.

The SNALINK LU6.2 connection allocates two LU type 6.2 conversations: one for sending data to the remote device and one for receiving data. For independent LUs, the remote LU name is the same for both conversations. For dependent LUs, a remote LU name is specified for both the send and receive conversations.

The Packets In and Packets Out fields are decimal counters that record the number of data packets received from the remote SNALINK LU6.2 and the number of data packets sent to the remote SNALINK LU6.2, respectively. These fields can be used to identify configuration errors that cause data packets to be lost or discarded. For example, the packet counters can be used to track how far a PING packet travels around the network circuit before it gets lost. Each counter incremented means the packet made it past that point.

For more information about the contents of the messages from the LIST MODIFY subcommand, see the message documentation referenced in Finding error message documentation. See the z/OS Communications Server: IP System Administrator's Commands for more explanation of the LIST MODIFY subcommand.