Slow Login Issues AD Integrated Servers

1. Login to the server and switch to root
2. Review the /etc/pam.d/crond file.  It should look similar to the following:
auth       sufficient
auth       required
auth       include    system-auth
account    required
account    include    system-auth
session    required
session    include    system-auth

3. Change the following line in /etc/pam.d/system-auth:

         account [default=bad success=ok user_unknown=ignore]
         account sufficient cached_login
4. Review the /etc/pam.d/system-auth.  It should look similar to the following:
auth        required
auth        sufficient nullok try_first_pass
auth        requisite uid >= 500 quiet
auth        sufficient cached_login use_first_pass require_membership_of=wheel
auth        required
account     required broken_shadow
account     sufficient
account     sufficient uid < 500 quiet
account     sufficient cached_login
account     required
password    requisite try_first_pass retry=6 minlen=8 lcredit=-1 dcredit=-1
password    sufficient md5 shadow nullok try_first_pass use_authtok remember=8
password    sufficient cached_login use_authtok
password    required
session     optional revoke
session     required
session     optional skel=/etc/skel umask=0022
session     [success=1 default=ignore] service in crond quiet use_uid
session     required 
5. Review the /etc/krb5.conf file.  It should look similar to the following:
 default = FILE:/var/log/krb5libs.log
 kdc = FILE:/var/log/krb5kdc.log
 admin_server = FILE:/var/log/kadmind.log
 default_realm =
 dns_lookup_realm = false
 dns_lookup_kdc = true
 ticket_lifetime = 24h
 forwardable = yes
[realms] = {
   kdc =
   kdc =
   admin_server =
   master_kdc =
   default_domain =
[domain_realm] = =
 pam = {
   debug = false
   ticket_lifetime = 36000
   renew_lifetime = 36000
   forwardable = true
   krb4_convert = false
6. Review the /etc/samba/smb.conf file.  It should look similar to the following:
   workgroup = wdc
   password server = *
   realm =
   security = ads
   idmap uid = 10000-20000
   idmap gid = 10000-20000
   template homedir = /home/%U
   template shell = /bin/bash
   winbind use default domain = yes
   winbind offline logon = yes
server string = Samba Server Version %v
passdb backend = tdbsam
load printers = yes
cups options = raw
comment = Home Directories
browseable = no
writable = yes
comment = All Printers
path = /var/spool/samba
browseable = no
guest ok = no
writable = no
printable = yes  
7. Install the following bind updates:
# yum install bind-utils.x86_64 bind-libs.x86_64 bind-utils bind-libs
8. Restart the winbind and samba services.
 # service winbind restart; service smb restart