rsync for /etc/passwrd /etc/samba/passwd

[Gurnish Anand]

Can somebody give me a quick education on sync'ing users, passwords and 
groups between 2 linux servers. Im using Redhat 7.1 as PDC and BDC using 
Samba. I want to sync mainly /etc/passwd, /etc/smbpasswd, /etc/group to 
get a consistancy going in the domain...
please guide me sync'ing passwords between them ..BOTH WAYS.....if a 
user changes a password on one computer it gets changed on the other...
and what is the probability of an error??

Please advice!!

Thanks,

Gurnish