What identification system to use?

Question

linux

Initial data: 80 workstations under Ubuntu, 25 - windows 7 and windows xp. All servers under linux.
It is necessary to organize a unified system of user identification. At the moment, Linux users are stored in ldap, Windows - AD. I want to get rid of AD. Previously, this was organized through openldap + samba3, but samba4 has its own ldap. FreeIPA is tailored for linux and works on Windows through crutches.
How do you organize single user credentials in mixed networks?

Answer 1

AD and no hemorrhoids

Answer 2

Used in due time here such piece www.zentyal.org . Quite tolerably worked, screw clients did not even cough.

Answer 3

I join the previous speaker. Leave AD online.

Answer 4

IMHO leave AD alone.
habrahabr.ru/post/174407
It's easier to use AD on linux than to migrate AD to linux.
If migrating AD to linux is fundamental, then Samba4.
"With the final release of Samba 4.2, the last series of Samba 3 has been discontinued!"
habrahabr.ru/post/216173