I-Spy returns an authentication error 951 when a user opens a database.
$ dbaccess sysmaster -
746: I-Spy: SQLERR -951 connecting to shadow server
These are some possible solutions for the 951 error:
Set INFORMIXSERVER to the shadowserver (database server name) in order to bypass I-Spy. If you are still seeing the 951 error, search other documents specific to the Informix server that addresses the 951 error.
Check if the password for this user has expired.
Check the permissions on the $ISPY_DIR/bin/realbin/ispy executable. It should be owned by root and have the set user bit ON for owner and group.
$ ls -l $ISPY_DIR/bin/realbin/ispy
-r-sr-sr-- 1 root informix 5816320 Apr 13 11:19 /work/ispy/bin/realbin/ispy
Check if the files /etc/passwd, /etc/shadow and ~user/rhosts files have proper read permissions for root.