[CentOS] MD5 and NIS

Does anybody know whether it is possible to enable MD5 passwords for NIS and
local passwords? Is it just a matter of running

authconfig --enablemd5

and new passwords will use MD5 and old ones will still work?

Of course using LDAP might be a "better" solution (if it was easy to
install).

I've tried googling and didn't get any useful answers...

Jeremy