User will login or set sessions at auth.domain.com and can use that session all the sub domains of that domain. the session will use across all sub domains.
where if the user visits sub1.domain.com or sub2.domain.com and they are not logged in, they get pushed over to auth.domain.com and can log in. sub1.domain.com and sub2.domain.com are two separate applications but use the same credentials.
To solve this problem, we can use the code below::
$some_name = session_name("some_name"); session_set_cookie_params(0, '/', '.some_domain.com'); session_start();
No need to Change in php.ini file
Note:: If you find the better solution please comment below..