Hi Steve,
thanks for your assistance,
 For RHEL5, I know its enabled. But based on your questions above, you
are
 asking 2 things. Where to put audit=1 and if pam_loginuid is right. For these,
 # cat /proc/cmdline
 and
 # cat /proc/self/loginuid
 would let you check. In the first, make sure audit=1 is there and in the second
 case, the output should be the uid under which you logged into the system.
 -Steve 
    [root@test /root]# cat /proc/cmdline
    ro root=LABEL=/ audit=1 rhgb quiet
    [root@test /root]# cat /proc/self/loginuid
    0
To narrow the circle;
we have some linux servers and a central log collector system. we are 
sending audit logs to this log system. this log collector system can 
parse such logs but this system confused at lines with "auid=4294967295" 
in audit logs.
i have tried everything but still this lines are coming:
    type=USER_ACCT msg=audit(1420656001.965:2804): user pid=6083 uid=0
    auid=4294967295 msg='PAM: accounting acct="root" :
    exe="/usr/sbin/crond" (hostname=?, addr=?, terminal=cron res=success)'
    type=CRED_ACQ msg=audit(1420656001.966:2805): user pid=6083 uid=0
    auid=4294967295 msg='PAM: setcred acct="root" :
    exe="/usr/sbin/crond" (hostname=?, addr=?, terminal=cron res=success)'
and
    [root@test /root]# cat /etc/pam.d/crond
    #
    # The PAM configuration file for the cron daemon
    #
    #
    session    required     pam_loginuid.so
    auth       required     pam_unix.so
    auth       required     pam_nologin.so
    account    required     pam_unix.so
    password   required     pam_unix.so
    session    required     pam_unix.so
so is there any other hints or what can i do esle?