Requesting that VTAM Verify Partner LUs

When your installation codes a VTAM® APPL statement to define an LU to VTAM, you must specify whether you want VTAM to verify the identity of partner LUs that attempt to establish sessions with the LU. To do so, set the APPL statement's VERIFY keyword to one of the following values:
Value
Meaning
NONE
VTAM should not verify partner LUs (the default)
OPTIONAL
VTAM should verify those partner LUs that have defined LU-to-LU passwords (session keys), as described in z/OS V2R1.0 Communications Server: SNA Resource Definition Reference
REQUIRED
VTAM should verify every partner LU.

If you request verification, VTAM verifies partner LUs by means of an associated session key. You can use the RACF® APPCLU class to specify the session key for each LU, as described in Defining LU-to-LU Session Keys.