Active Directory Auth

Install Prerequisites:

yum install -y samba pam_krb5 krb5-workstation samba

Configure kerberos:

Edit /etc/krb5.conf

# Configuration snippets may be placed in this directory as well
includedir /etc/krb5.conf.d/

[logging]
 default = FILE:/var/log/krb5libs.log
 kdc = FILE:/var/log/krb5kdc.log
 admin_server = FILE:/var/log/kadmind.log

[libdefaults]
 dns_lookup_realm = true
 dns_lookup_kdc = true
 ticket_lifetime = 24h
 renew_lifetime = 7d
 forwardable = true
 proxiable = true
 rdns = false
# default_realm = EXAMPLE.COM
 default_realm = MYDOMAIN.COM
 default_ccache_name = KEYRING:persistent:%{uid}

[realms]
 MYDOMAIN.COM = {
  kdc = AD_SERVER.MYDOMAIN.COM
  admin_server = AD_SERVER.MYDOMAIN.COM
  default_domain = MYDOMAIN.COM
 }

[domain_realm]
 .kerberos.server = MYDOMAIN.COM
 .intelgd.com = MYDOMAIN.COM
 intelgd.com = MYDOMAIN.COM
 intelgd = MYDOMAIN.COM

[appdefaults]
 pam = {
  ticket_lifetime = 1d
  renew_lifetime = 1d
  forwardable = true
  proxiable = false
  retain_after_close = false
  minimum_uid = 0
  debug = false
 }

[realms]
# EXAMPLE.COM = {
#  kdc = kerberos.example.com
#  admin_server = kerberos.example.com
# }

[domain_realm]
# .example.com = EXAMPLE.COM
# example.com = EXAMPLE.COM

Test it out:

kinit user@MYDOMAIN.COM