security/krb5/krb5.conf

[realms]
   EXAMPLE_0.COM = {
      kdc = kdc.example.com
      kdc = kdc2.example.com
   }

   EXAMPLE_1.COM =
   {
      kdc = kdc.example.com
      kdc = kdc2.example.com
   }

   EXAMPLE_2.COM = {
    kdc = kdc.example.com
    kdc = kdc2.example.com
    inner = {
        aaa = nnn
    }
   }

   EXAMPLE_3.COM = {
    kdc = kdc.example.com
    kdc = kdc2.example.com
    inner =
    {
        aaa = nnn
    }
   }